The Testarossa heater thread!

I've had my car coming up two years now and the heater has never worked properly. Dial up the heat, set the fan speed and operate the push button controls for either fresh air or recirculated air and the heater worked perfectly fine. Except after about 15 - 20 seconds the air got cool (ambient). Hit the stop button, wait for 30 - 45 seconds and then hit the fresh air button, and you have heat again, for another 15 seconds anyway. Impossible to drive the car in bad weather as there was no way to defog the windscreen.

I've had the dash out to replace the windscreen so this is the perfect time to try and fix the problem. No passenger seat and no trim to bother about so access to the heater box is pretty good.

I started today by checking the return air from the cabin. Little vent near drivers hand. There is a small electric motor in there which runs all the time when the car is turned on. The sensor itself has two wires going to it. With the car running I had 4v on one of these wires but never got a reading on the other one???

Then I checked the sensor that is behind the cabin vents. It's a long white probe and goes right back towards the actual heater core, It also had 4v on one side and 0v on the other side with engine running.

Then I moved on to the heater tap solenoid. This is mounted on the wheel arch behind where the passengers feet would be. It has two wires going to it. Brown and brown/white. I measured 10.5v here on one wire and the other goes to earth.

Next I removed the solenoid for inspection and testing. To do this I removed the two 5/8 heater hoses and joined them together using a 5/8 double ended brass barb joiner. I removed the solenoid and stripped it down. Inside there is a fine mesh screen which was completely gumed up with fine silt deposits. I rinsed and blew all of this off until it was clean and I could see light through the mesh screen. I refitted the electrical components to the body of the solenoid and without any pipes attached I could see the solenoid operate by looking inside where the pipes go.

The top inlet pipe on the solenoid unit has direction arrows for water flow. There are no marks on the bottom hose connection point. The solenoid appears to operate properly and closes off the section between the upper and lower pipes.

It's really hard to understand how it works though. I have to do some tests to see under what circumstances it's open and when it's closed. I tried a number of different combinations and expected that somewhere along the way, that the solenoid would slowly open around about 15 - 18 seconds after turning on the heater and therefore show me the fault, but it never did.

With the two hoses joined together I got constant heating, but naturally I couldn't shut off the water flow and therefore wasn't able to get any cold air from the air con unit to come through when I dialed in max cold.

It appears to be a very complex system to operate, but there must be some defined parameters in there somewhere to allow operation and testing.

Then I bailed out for the day and came inside to do some research. TR owners manual talks a bit about the heater operation. None too clear mind you. A lot of DOES and DONTS which seem to make no sence at all.

 

Here's an extract form the Owners Manual that discusses the correct operation of the heater system:

AIR CONDITIONING AND WINDSCREEN DEFROSTING

The acclimatisation assembly includes air conditioning, ventilation and heater system and is equipped with an electronic control unit, which following the first minutes of transient condition, guarantees an almost constant temperature inside the passenger compartment.

It can be adjusted through control nos. 12-13-14-15-16-17 (Fig 32) as follows (steps A, B and C)

A) Select the type of operation required, by pushing of the 4 buttons nos. 13-14-15-16 (Fig 32).
Pushing button 13 (stop button): no air circulation; the external inlet for ventilation air is closed, electric fan stationary and control unit OFF.
Should never be pressed when the car is started.
Never press when running whilst the air conditioner is sending cold air.

Pushing button 14 (recirculation air button): summer air conditioning, the external inlet for ventilation air is closed, the inlets for internal recirculation are open. Should be pressed only in summer for maximum efficiency of the air conditioner.

Pushing Button 15 (fresh air); ventilation, air conditioning in intermediate seasons heating, the inlet for external ventilation air is open. Should always be pressed in normal conditions. This allows cold or warm ventilation with external air.

Pushing button 16 (windshield demist): ventilation is directed mainly to the windscreen for defrosting and demisting; the inlet for external ventilation air and the outlet to the windscreen base are open, the main outlet at the centre of the console is closed. Should be pressed only when it is necessary to defrost or demist the windscreen. Never use when the air conditioning system is adjusted for cold temperature. A micro switch connected to defroster flap operates the compressor for a period of 3 - 3.5 minutes to cool and dehumidify the air, thus speeding up windscreen defrosting.

B) Adjust the air speed by rotating knob 17 (fig 32). Air speed increases with clockwise rotation of knob 56.

C) Adjust the air speed by rotating knob 12 (Fig 32), with the following conditions applicable:

Maximum cold: with knob at the limit stop in anti-clockwise direction (beginning of blue segment)

Maximum heat: with knob at the limit stop in clock-wise direction (end of red segment). Temperature can be varied from 18 to 32 degrees.
Depending on outside conditions, the cooling system will function if the knob is in the blue zone, the heating system will function if the knob is in the red zone.

Intermediate temperatures: can be selected in other positions of the adjustment range, where a clock-wise rotation of knob 12 brings decreasing cold (with blue segment becoming smaller) and increasing heat (with segment becoming wider).

Initially adjust in the boundary area between blue and red segments; after approximately 15 minutes (time required in order to bring system in steady operating condition), rotating the knob a few degrees if you wish a temperature slightly different from what initially selected. Later on never alter the position of this knob. Only move it very little in order to compensate differences in the external ambient temperature.

 

So there are a couple of interseting parts to the operation of the heater. Unfortunately FChat doesn't have many post formatting tools. I would have liked to highlight the areas of interest or make them bold at least.

However:

Under Section A of the manual and refering to the STOP button (13):

"Should never be pressed when the car is started. "
"Never press when running whilst the air conditioner is sending cold air."

Also under section A and discussing operation of button 14 for recirculatory air:

"Should be pressed only in summer for maximum efficiency of the air conditioner"

Then followed by instructions regarding button 15 for fresh air:

"Should always be pressed in normal conditions."

Then go right to the bottom of the previous post where the owners manual discusses intermediate temperatures attainable using Knob 12 (temperature).

"Later on never alter the position of this knob."

What's that all about?





So there are obviously some specific issues relating to proper use of the AC / Heater system on al model TR's.

What happens if you inadvertantly press the STOP button when the car is started or whilst the AC system is sending cold air? Does anyone have any ideas?

Why should we only press button 14 in Summer?

Why should button 15 be 'always pressed in normal conditions'? What's this mean?

And the last section regarding the intermediate temperature knob. NEVER alter position of this knob!!

Has anyone had previos (similar) experiences with their heating systems? Please post up here so we can all learn from the various problems and fixes to try and understand how this system works, why it fails, and how to repair it.

 

The heater tap solenoid is an interesting litle beast on it's own.

There are embossed markings on the upper hose entry port showing direction of flow, yet nothing on the lower port. There is also a fine mesh basket filter. When the solenoid is activated it extends and closes off the exit to the bottom hose. Water is then free to flow through the mesh filter but then what? Does it flow up into the centre plunger? Is that solenoid central spring some temperature related device that is actually immersed in hot water and has to be kept very clean by the filter.

Very complex little device. Anyone ever pulled one apart?
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Something is obviously lost in translation in the OM. The words they use are probably a little harsher than necessary - never, only, always, etc.

A long time TR owner did tell me about the temperature adjustment on the car - try and set it once and forget about it. (Certainly that does not work for all climate conditions as we all know that 75F is great in the winter but not cool enough in the summer.) I think his real point is that the temperature adjustment knob does interact with the entire system and tries to maintain a constant temperature by opening/closing the solenoid properly to achieve this. Patience matters here as the changes are not instant. I have noticed that if I endure for a while the cabin will moderate and "maintain" a temperature. If, on the other hand I am constantly fiddling with the knob I am always too hot or too cold - there seems to be a 5+ minute lapse to attain a noticeable change in ambient air.

Just realized I am adding my own babble to the mix...

 

It is a little more complicated than this -- the logic is:

1. Whenever the key is "on", the brown (M) wire should be +12V (your 10.5V is probably close enough if you didn't have the engine running).

2. When the "STOP" button is pressed, the brown/white (MB) wire is always held at ground by an oddball relay on the AC unit so the voltage measured from the M wire to the MB wire should be a constant +12V - this holds the EM water valve closed.

3. When the key is "on" and any of the other push buttons is pushed, the oddball relay actuates, which removes the constant ground signal from the MB wire, and the MB wire (which is also connected to the AC ECU) is now controlled by the ACU ECU which either puts the MB wire to ground or not depending on what it "thinks" is required based on the sensor inputs. To get variable hot water flow rates, the AC ECU rapidly switches the MB wire to ground or not ground (i.e., PWM control) which rapidly opens and closes the EM water valve and gives an average flow rate thru the valve somewhere between fully open and fully closed (although, instantaneously, the EM water valve is either full open or fully closed).

Bottom line is to measure the voltage between the M and MB wires at the EM water valve:

1. Key "on" and "STOP" button pressed = should be +12V (water valve fully closed)

2. Turn heater "on" (at max hot) = should be 0 V or near 0 V (water valve fully open)

3. Note what the voltage does when the hot air goes away after the ~15 seconds (when the cabin can't possibly be as warm yet as the requested temp) -- if it stay 0 V = something wrong with the valve (the system is trying to keep the valve open); if it goes back to +12V = something wrong with the control electrics (the system wrongly "thinks" it needs to close the valve).

Do you have a TR WSM to make the other input sensor checks?

PS IMO, the OM stuff is just a bad/error in translation as Curtis noted. The "STOP" button should never be pressed when starting, because it should already be pressed before starting -- that note should've said "Ensure the STOP button is pressed before engine starting"; the recirc note should've said "Should only need to be used in summer for maximum efficiency of the air conditioner"; and the "Later on never alter the position of this knob." is only to mean "you shouldn't need to alter the postion of this knob once the system is working at the temperature you want".

 

The translation is terrible and you are trying to believe the English words as correct information. The message is not always what the words say. The interesting part though is even in the Italian the information is not all that correct. The people who write the manuals have no technical background and much misinformation is presented. You have to know how the system works and just use the data. Those are all general comments on Ferrari manuals. In the case of the TR the diagnostic specs are incorrect also.

Bottom line.....If you are counting on the TR manual to fix a TR climate control system you are screwed.

All the decent Ferrari mechanics I worked with over the years either had a notebook in addition to the manual or kept copious notes in the manual itself to add to or correct the information in the manual. Those would be in addition to notes we took in the classes.

 

So it is OK to change from AIR to OFF while you are driving? And then back over to HEAT? As in, if I am driving up a mountain and it gets too cold inside?

If not, I guess we sure paid a lot of money for the only car in the world that cannot accempt this simple control sequence...

 

Fantastic info once again Steve.

Yes, I do have the other sensor checks from the WSM and will do them over the weekend when Suzie can help. Especially for the 0 - 10 000 ohms check on the heat knob. (My arms aren't that long).

I'll ask a curly question then.

Firstly, just to check that my connections are right. Does the water flow to the heater first, thru the core then into the top of the solenoid and then return to the rear of the car from the bottom of the solenoid? I need to know that mine was hooked in correctly.

Then, would it be at all possible when doing an engine out service to swap around the feed and return lines to the heater system at the engine end of the car?

Now the curly question:

The solenoid upper input has two direction arrows which indicate direction of flow. This one comes from the heater unit. When you look into that connection and into the solenoid valve you can see a fine wire mesh strainer. I pulled my solenoid apart and found this wire to be nearly fully coated with scale. I don't think water was getting through there. Under the base of that strainer basket there is a fine 1/16th hole which allows water to get into the long silver shaft that goes right up through the centre of the solenoid and which houses the spring for the brass shaft.

Why is the strainer there, and for what purpose is water allowed to enter into that shaft. It cant be to cool the solenoid, although I expect this solenoid to run stupidly hot when the AC is turned on and it is energised to shut off the water flow.

Any ideas?

 

I think I'm screwed then Brian. Biggest problem in Australia is the lack of Testarossa's! As they were never sold here there is very little dealer or repairer expertise, and the chances of finding someone with a repair book full of notes - zero to none.

When you say that the diagnostic specs are incorrect also, can you elaborate a bit on this aspect please. The WSM gives me a chart of resistance values to check for the three system sensors and for the hot/cold dial. These appear to be quite specific figures so I wouldn't have thought these would be incorrect, but I'm certainly here to learn from those with wisdom.

 

Yes, that seems correct -- at least it matches what's shown on pages 45-46 in the OMs. Hot water exits the tubes coming from the top of the cylinder heads, goes to the heater core, out the heater core to the top of the water valve, and out the bottom of the water valve back to the tubes that connect to the inlet of the water pump. I don't think it would be possible to swap the hoses at the engine due to the different lengths.

My guesses would be cooling as even when the STOP button is pressed the coil is always energized or maybe seal lubrication or to prevent a seal from drying out. The cross-section drawing of the valve is good, but it really doesn't show all the details in a strict technical fashion, but if there is any sliding motion between the components, I would say the screen's functions was just a way to prevent some large chuck of crude for getting stuck in a sliding joint area (if present) while allowing the water to reach the area.

 

PM sent

 

Some new information has come to light. Thanks so much to Waltos91 for pointing me in a new direction.

Under the centre of the dash are four relays. Numbered 15, 16 and 17 x2 on the parts diagrams.

15 - Timer relay. Part number 123509 Cost from Ricambi $178.00
16 - Control relay. Part number 6247 8900 Cost from Ricambi $15.00

17 - Control switch relay. Part number 4013 0007 Cost from Ricambi $13.00


This tells me that three of the relays are basic items, but the timer relay must do something pretty special to be so expensive.

So I wandered out to the shed to check my relay 16 and I find that all four relays have been changed and sitting in their place are four Ford relays P6STD number F0AB-14B192-AA

I expect that therein lies all of my problems??

As my car is RHD and all of the diagrams show LHD cars, I don't know which relays are supposed to go in which positions even if I had new ones. Also, are these standard Bosch or Hella relays and has anybody ever done a comparative to genuine parts.

The cost of the genuine parts (except for the timer relay) is fine, but the availability isn't. I can order from Eurospares or Ricambi but time is the issue as the car is in a million bits and the two supliers are on the other side of the World.

Then there is the exorbitant cost of the timer relay. What does it do, and can I supplement something else (other that a Ford lighting relay!)

What are the chances of damage to my AC ECU from having these wrong relays fitted and no timer?

 

Been a busy day.

I located another car and checked the relays. They are reversed to the USA model with the larger timer relay being closest to the rear of the car but on the LHS (USA Drivers side) so reversed to the parts diagram.

I removed the four relays for inspection to check for identifying marks.

Relay 17 - (2 of) ITALAMEC 12v 160 4320629 appears from the drawing on it to be a 5 pin normally open relay. Could it possibly be 12v 160amps, seems huge amperage where a common f pin normally open is around 30amps.

Relay 16 - Also ITALAMEC 056 12v but no full part numbers to identify it and also no circuit drawing on it. It's a 5 pin relay with two No. 87 pins, though one 87 pin (the centre) has been cut down to the base level so there must be only four wires to connect it in the base where it plugs in.

Relay 15 is the timer relay. 4 pins but larger than the others. Looks more like a square flasher can. It has a symbol with a round circle with I in the middle and the number 422. 12v 180 sec. It's the expensive one from the dealer. the pins are numbered 85, 86, 87 and 30/51. I've never seen a relay with 30/51 before. 30 is always direct battery feed for me.

I checked some cross reference areas and found that ITALAMEC 4320629 relates to Lucas SRB521 and Lucas SRB528, NAGARES RLPS/5-12, Bosch 0 332 015 151 and Hella 4RA 003 510-131 but so far nothing on the other relays.

 

Well I found out why the timer was so expensive, it's common to all testarossa's and to the F50!!!

Ferrari F50 TIMER FOR ENGINE BONNET ELECTRO FAN - No wonder it's got a gold plated price tag!

Still hunting for an alternative.

Anyway - Control relay 16 is definately a Normally closed relay. Bench tested I have continuity between pins 30 and 87.

Relays 17 and 17 is confirmed to be a normally open relay.

 

Message for Steve M.

It appears that your stored PM message quota has been exceeded and all PM's are being rejected. Also tried to email you but the comcast address appears to be dead. Can you advise current email address please to [email protected]

Thanks, Rob H.

 

Relays 17 are just the garden variety 30A ...113 Bosch relay that, as you noted, is normally open, and, when energized, terminal 30 is connected to both terminals 87 (and both terminals 87 are always connected together).

Relay 16 is what I earlier called the "oddball" relay, and is normally closed, but the 87 terminal label is technically incorrect IMO and should really be called 87a (which is what it is labeled in the WSM schematic). What's oddball about it is that the 87a terminal is not in the same physical position as the 87a terminal on the garden variety ...101 Bosch relay. You can substitute a ...101 relay for this relay if you move the corresponding 87a wire in the socket to the center position. David Waltos had this same problem where someone had used an incorrect relay in this position -- if you had made the voltage measurements I had suggested, you probably would've found the same problem that he had where the voltage logic at the water valve was backwards because of the incorrect relay -- i.e., he had STOP button pressed = 0V between M and MB (so water valve was always open) and HEAT ON = 12V between M an MB (so water valve always closed and no heat). Also, IIRC, at the time (circa 2005), the "official" relay 16 part from the F supplier was wrong so make sure:

1. this relay is normally closed -- i.e., 30 is connected to 87a (or whatever it is labeled) when unenergized, and 30 not connected to 87a when energized, and

2. the wire in the socket intended for the 87a terminal is in same place as the male 87a terminal on the relay.

IMO, it's better to use a ...101 relay and move the wire in the socket, if necessary (what's weird is that on your F113B schematic they actually show a ...101 relay, which would require using the center postion tab; however, since you say that that center terminal is cut off on the relay in other F113B? TR you are looking at maybe it's a change that only got onto paper or was a bit messed up in implementation).

For the timer, you probably won't find a substitute (and even if you did, it probably wouldn't be much cheaper) -- just pay the ~$200 and be thankful it's not $400

 

Hi Steve,

Yep, I'd started doing the voltage checks this morning when a PM came thru from DW explaining his past issues. Hence I checked my relays and found all the Ford ones sitting in there instead. AT that point I discontinued further checks as it appears that I have located the culprits.

I was able to get to an original relay 16 from another car and note that it is a five pin relay (normally closed) and the pins are labelled 30, 85, 86, 87, 87 yet the middle pin 87 has been cut off at the relay base. The two 87's are definately connected internally but the middle one cannot plug into the relay socket in the car, leaving the top pin 87, bottom pin 30 and the two side pins 85 and 86 as being the only ones that will make connection when it's actually in the car.

So to keep the car as original as possible I'll pick up a normal 5 pin relay (normally open) and remove the middle 87 as per the factory and use that. Can you tell me the amperage of the two 17's and the 16 please. My local parts shop stocks Hella and Bosch but they are 30amp and that may be too high.

Makes you wonder why Ferrari didn't just use a four pin relay in the first place in that position. Also strange that they used Bosch relays predominately yet in this area they are Italamec.

 

Did you mis-type here -- relay 16 needs to be NORMALLY CLOSED whether you can find a 4-pin or get a 5-pin and cut off the center pin.

The relay 17s should be 30A. Relay 16 maybe could be less, but anything 15A~30A is probably fine.

Because it wasn't F who did the original design -- it was the AC/heater unit vendor. Initially, they did use a special 4-pin relay, but it must have gone out of production so they went to the modified 5-pin relay. IMO, if F had done the design, they would've used a ...101 relay, even if it was a little more expensive, rather than use an uncommon 4-pin relay that isn't used anywhere else in their cars.

 

Hmmm, It looks like this $200 relay, has nothing more than a delay circuit in it. You should be able to cobble one together using the ford relay that is in there and then adding a delay circuit to keep the relay on for three minutes after power is removed. You could use something like the circuit here: http://www.electronics-project-design.com/timedelaycircuit.html
there are lots of 555 timer circuits out there and the parts are dirt cheap.
You may want to visit your local high school electronics teacher and have them build it as a student project for you if electronics is not your thing.

 

Must be my lucky week. Not only was I led to the right area by you great blokes, but having found the issue I then went searching for replacement parts.

I located a heavily front hit 87 TR in the UK and was able to source all four relays (factory genuine) for 60 GBP inclusive of post to Oz. I reckon by around Thursday I should have the heater working and then be able to start putting the dash back together after having the top section re-skinned around the vents and the new weindscreen put back in.

Ah...I forgot, I still have to make the drivers side floor duct. I manufactured a passengers side one as I had a good picture of that one, but I'm struggling on the drivers side as no one seems to have one intact that they can take a picture of.

Ever tried manufacturing something from scratch when you have no idea of what it looks like, only what it is supposed to do and where it goes. It's tricky!

 

Dear Ferraristi,

I took these photos JUST FOR YOU when Jimbo and I were working on his 512TR.....


Now for payback, you have to post photos of your re-leathered dash, windshield....what NOT to do while you're "in there" and lastly a tall thin blonde in a very skimpy bikini standing over your car jestering..."all done"

....a small price to pay, I think.


BTW,

Interesting info on the relays. What's noteworthy is that how you would have heat for 15 seconds.....perhaps the lack of the timing relay, it timed out.

I always thought that the HVAC system was a relatively simple system.....thanks for proving that wrong.


Shamile

Freeze.....Miami Vice !
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Yeah, yeah, yeah.

I really have to come to Florida one day just to thank you for those pics too. 2009 might just be the year for a USA trip, if our dollar still holds water then.

I made the pass side vent from that picture, but a bit hard to make the drivers side when Jimbos' one has broken the end off!!

The HEVAC is far from simple, but when I get five minutes to scratch my arse I'm going to do a write up on ferrariaustralia.com of how it works and what I found. Probably ask Steve M to do the supplemental electricals for the write up or at least go over my data. Then this info can be recorded and we will become 'those old Ferrari fix it guys who make notes in their WSM's'!! hahaha.

Now, the dash pad went back in this afternoon and looks superb. Pics to follow....................promise

The windscreen, well that's been a saga. After the factory sending three windscreens with the wrong coloured tint (green instead of bronze) they finally got it right. Graduated ceramic dots at the top, perfect antennae in the centre of the screen, but it has graduated ceramic dots along the bottom also, just like a 512TR which cover 90% of the vent holes from the sun. Seems the factory have revised the screen to protect those vents so it's now not possible to buy the original style that is clear along the base.

At $5500 AUD plus $1200 for the trim kit, it's not something you want to do every day either!!

A few things to do over the next three weeks.

-: Manufacture the drivers floor vent from the heater unit.

-: My car has the blaupunkt amp behind the passenger footrest plate and I'm replacing that with an Alpine 4x150 amp. Original speakers have been replaced with MB Quart in the stock (hidden) locations and the tweeters upgraded to MB Quart also. The head unit is to be a JVC Exad with the 3.5" wide screen connected to a reverse camera. It will be a nice, discrete stereo install with the added functionality of the camera, so will take some time to integrate properly in a way that can be reversed if ever required back to the factory blaupunkt.

-:Once the stereo is fitted and the interior all back together then it's time to put on the newly refurbished KE Jetronic system to hopefully cure this lean running issue and the associated bad driving habits that the car exhibits.

-: If the new KE system doesn't fix the issue, then I'll have to pull the engine as I think the only thing left that could be affecting it will be cam timing. Maybe one cam is a degree or two out. Last cam belt service was 12500kms ago in the UK, back in May 2006. Maybe the cams were set to the marks and not by dialling them in. Supposition only at this point.

Now once all that is done, and the details posted up on my web site for the world to see, then I'm going out hunting for that tall thin blonde in a very skimpy bikini!!!

 

No, what was actually happening was that the heater tap was working in reverse order of what it should have been thanks to the number 16 relay being all wrong. Water was running through the heater all the time keeping the core nice and warm. I never noticed coz I always drive with the windows down or AC on. Never needed the heater before except one or two days.

On those days I would dial in max heat and 3/4 fan, then hit either recirc or fresh air buttons to start the HEVAC system. What actually hapened then was the heater valve closed and stopped water flow through the core. With the fan blowing ambient air over the heater core with no water flow, it was taking 15 seconds to cool the hot core back to ambient. No heat at that point!!

Ah well, we all live and learn.

I'm just pleased that I have you guys to point me in the right direction, and my old Ford and Toyota mechanical skils to actually get the work done. I'd be in the poor house otherwise, or have a very expensive garage ornament.

My car was a very well kept UK examle with a really good service history and three owners yet somewhere, somehow, the occasional cowboy has had his head under it. On reading a few earlier threads today in other sections, I must say, imagine buying a TR that was actually a bit of a known sh1tter. We can only shake our heads in horror at what we might find in a car like that.

 

How timely that I ran across this thread. I will be investigating the lack of heat function in mine as well. Zero heat. Gladly the A/C works great which is by far much more important to me than the heat though it would be handy on those really rainy days on occasion.