| Author |
Message |
CraigFL
| | Posted on Friday, February 02, 2001 - 6:47 am: | |
Rob...
Yes you are correct, the two fans on the radiator are connected as essentially one fan for cooling the radiator. There is another fan for just the condenser. Apparently, this is an improvement on the cooling over the 308. By moving the condensor to another location (this means the hot exhaust air from the air conditioning is not interfering with the radiator cooling), and using two radiator fans that are both "on" together, cooling must be improved.
The airflow thru the radiator circuit is thru the front grill, thru the radiator, thru the fans and exhausting warm air out the top louvers in the hood. When the thermostatic sensor is "on", the airflow is the same but enhanced by the fan -- sucks air thru the radiator and exhausts warm air thru the louvers.
I guess you're back down to changing that thermostatic sensor then...
P.S. I was working with the 1989 wiring diagram yesterday because that was all I had available at work. I did verify last night that this same circuit exists on my 1986 wiring diagram. |
'75 308 GT4 (Peter)
| | Posted on Thursday, February 01, 2001 - 7:46 pm: | |
The reason why mine and other 308's have one of the fans come on with the A/C, is that the condensor is mounted directly IN FRONT of the rad. Both fans are directly IN FRONT of those (condensor & rad). It seems 328's have separate condensors so they would have their own fan. The 328 rad would have two fans because its narrow and wide and that both come on at the same time from that temp sensor signal.
It'll be interesting how you solve this Rob. I noticed my car only one fan would come on (!) The A/C fan never did. It was replaced by the previous owner and although it's still a Lucas, it has a different # and shape to it, plus crude wiring done by that mechanic. I'm hoping its just that. |
Rob Lay (Rob328gts)
| | Posted on Thursday, February 01, 2001 - 5:22 pm: | |
Just so I understand, my 2 front fans are for the radiator only? I have a 3rd fan behind the head light just for the AC?
Also, it seems the radiator fans "suck" heat out vs. putting air in to cool? All the air exhausting out of the fans is warm. |
Steve Magnusson (91tr)
| | Posted on Thursday, February 01, 2001 - 5:00 pm: | |
Then you are obviously correct, and Rob should not apply the "right hand rad. fan comes on with the AC" rule to his situation. |
CraigFL
| | Posted on Thursday, February 01, 2001 - 4:41 pm: | |
Steve...I have an 86 328GTS as does Rob. My Condenser is located behind and below the passenger side headlight and not near the coolant radiator. I assumed that the third fan shown in the wiring diagram (#102) is related to that condenser. |
Steve Magnusson (91tr)
| | Posted on Thursday, February 01, 2001 - 4:35 pm: | |
CraigFL -- Steve J.'s 328 wiring diagram is for the 1989 which has a completely separate fan for the AC condensor as you noted. I think Rob's 328 is an ealier model year so it may be more like the 308s (but I'm just guessing). My ex-'78 308GTS was also configured with an extra relay like Peter's 308GT4 to turn on just the R.H. radiator fan with the AC.
Rob -- what year is your 328? Does it have a separate fan on a separate AC condensor, or is the AC condensor mounted against the radiator like 308s? If it's like a 308, it should have a relay called: "Relay for radiator right fan with operating air conditioner" or something like that (which, as CraigFL noted, the 1989 does not). |
CraigFL
| | Posted on Thursday, February 01, 2001 - 4:12 pm: | |
I know that's what Peter said for his GT4, but the schematic I checked for the 328GTS shows that the radiator cooling fans are not in the Air conditioning circuit. Unless I missed something... you can look at:
http://ferrari.jenkins.org/books/1989_328_wiring.pdf |
Rob Lay (Rob328gts)
| | Posted on Thursday, February 01, 2001 - 3:05 pm: | |
isn't one fan supposed to come on when you turn the AC on, no matter how cold it is? Thanks. |
CraigFL
| | Posted on Thursday, February 01, 2001 - 2:28 pm: | |
I checked the 328 schematic and the system is set up to turn both fans on when the coolant gets to a certain temp - as sensed by that thermostatic sensor below the RH fan on the radiator. There is a seperate relay and fuse for each fan, but only one thermostatic sensor to turn both relays on.
Therefore, if the fans don't come on ever, as you previously stated, and they do come on when you touch the two leads together of the thermostatic sensor, the thermostatic sensor must be bad. |
Rob Lay (Rob328gts)
| | Posted on Thursday, February 01, 2001 - 11:10 am: | |
Well, I've already said that both fans work when touching the two leads to each other. I just got another idea. The AC fan wouldn't come on before when the leads were attached to the sensor unit. However, I would think the AC fan would still turn on, even if the thermostatic sensor wasn't sensing heat. Maybe it's a bad electrical through the thermostatic sensor? The grounding is fine because it works when I touch the leads. |
CraigFL
| | Posted on Saturday, January 27, 2001 - 7:38 am: | |
My 2 cents again.....
The thermostatic sensor (on the radiator) is very accessible on the 328. If it were me, I'd change it hot(but not too hot!). Like Peter said it could be siezed or at least tight and the aluminum radiator will probably expand more than the sensor body. I'd also Kroil the threads for extra measure (I'm a big believer in this stuff...) Get ready with the new sensor all lubed up and ready when the old one comes out. You will lose a little coolant but shouldn't be too much (don't forget the glove for protection). |
'75 308 GT4 (Peter)
| | Posted on Saturday, January 27, 2001 - 1:30 am: | |
The only problem may be that it'll be on tight. I'm not sure, but if the rad is aluminum and the thermo switch is steel, there could be some seizing. I had a similar problem with my oil cooler. Had to take it into work and heat the nuts up with an oxy-acetylene torch, then the hoses came off (hoses use hydraulic-type fittings: steel on aluminum cooler threadings). Plus, you'll have to drain the cooling system, etc...
If you don't have the time, tools, space, you'll be better off taking it to Norwoods.
Whenever you go to an auto parts store, never say its off a Ferrari. They matched my voltage regulator with an equivalent and it only cost me $14 Canadian! You say its from a Ferrari and they'll check their "other" catalogue. |
Rob Lay (Rob328gts)
| | Posted on Friday, January 26, 2001 - 7:54 pm: | |
Thank you very much. This was a good little auto tech lesson for me. I think I'm going to still replace the thermostatic sensor because of some stop and go traffic here in Dallas. I've had the car 4-5 months now and never had it overheat. The only time it got close was when it was idling for 10 minutes while I took pictures.
Anyone know how much the part is and how tricky it is to replace? I think I'll still leave it too the experts though. |
'75 308 GT4 (Peter)
| | Posted on Friday, January 26, 2001 - 7:00 pm: | |
The thermostat is a mechanical device housed in the neck, visible at the front of the motor at the top, in the middle of the "vee", above the water pump. The coolant basically circulates through only the engine, until the temp rises, the thermostat opens and coolant starts flowing through the pipes to the rad. When the coolant continues to heat up, even though its now flowing through the rad, thats when the thermo sensor on the rad trigures the fans. The thermostat has no connection with this switch on the rad.
Hook your wires together and leave'em or replace that thermo switch. |
Ben Lobenstein 90 TR (Benjet)
| | Posted on Friday, January 26, 2001 - 6:51 pm: | |
not that I'm a 328 guy...
but there should be a mechanical thermostat on the engine, this would open (via expansion when hot) a valve, when it reaches the proper temp and begins to circulate the coolant (and water mix) thru the radiator(s) using the water pump...in addition you should have a thermostatic sensor (I would assume on the radiators) which when they reach the proper temp would (just guessing here) tell a relay to turn on the radiator fan(s).
If you don't overheat when moving (even with your fans not working) then your thermostat is probably just fine. If you didn't have the coolant circulating in the radiator (thermostat failure) you would EASILY overheat, under most ANY circumstances.
That hopefully clears up the difference between a thermostat (mechanical) and a thermostatic sensor(electrical).
that's my $0.02
-Ben |
Rob Lay (Rob328gts)
| | Posted on Friday, January 26, 2001 - 6:08 pm: | |
Ok, I'm really confused now. The car doesn't overheat when I'm moving because air is getting to it. I haven't tried idling it for very long with the fans on to see if it still overheats. I assume it won't overheat with the fans running. When I was talking about the thermostat, I was talking about the same thing as the thermostatic sensor. Is there a difference? Obviously the electricals are fine and the electric fans work fine. So it's only whatever those 2 leads were connected to. |
Steve Magnusson (91tr)
| | Posted on Friday, January 26, 2001 - 4:55 pm: | |
Rob -- Craig's right here. If you had a problem with the thermostat you'd overheat when moving too. |
CraigFL
| | Posted on Friday, January 26, 2001 - 4:15 pm: | |
Don't forget that touching the two wires only means that the fans, fuses and relay is working. The thermostatic sensor that you removed the leads from may not be working. How about driving the car with the fans on all the time (wires connected together and taped) and see if the car still overheats. |
Rob Lay (Rob328gts)
| | Posted on Friday, January 26, 2001 - 3:50 pm: | |
Ok, I finally disconnected the leads and put them together. Sure enough, both fans came on full blast. I'm taking it into Norwoods next week to have the thermostat looked at.
Thanks for everyone's help. |
CraigFL
| | Posted on Monday, January 22, 2001 - 6:32 am: | |
Rob... I checked mine out this weekend to be sure too. Very simple. Remove the two leads on the over temp sensor-- on the radiator, passenger side, below the fan-- just two push on terminals and easy to get at. Turn the car on, touch the two wires/connectors together and the fans should go on. If they don't, first look at the fuse(see owners manual) and second suspect the relay(also see owners manual). Should be a simple job to change either. |
Rob Lay (Rob328gts)
| | Posted on Sunday, January 21, 2001 - 4:59 pm: | |
Well, I took a better look at the problem today and neither of the two fans come on for anything. They don't come on when the AC is on and they don't come on when the temp rises above normal. I'm thinking I bought the car like this because I've never had situations were I idle it too long, except initial warm up. I'll have Norwoods look at it this week. |
'75 308 GT4 (Peter)
| | Posted on Friday, January 19, 2001 - 3:34 am: | |
On my GT4, the curb-side (passenger's) fan comes on with the air-conditioning system. Driver's side fan is the one controlled by the thermo switch. A few of the 308 guys here in the Northwest had such a problem with failing switches, they jumped the connections just like "ifrgt" said and left it. They now have two, permanently running fans with no further problems. I've noticed sitting in traffic jams that my temp did get into the 200°'s but no further problems. After 20 MPH, the speed of the wind is sufficiant to cool the rad without the fans (so yes, when you got running again the temp dropped). |
Bret M
| | Posted on Wednesday, January 17, 2001 - 5:40 pm: | |
Before you get deep into it check the coolant level in the expansion tank. It should be 6 cm below the cap (I just fill it up all the way and let the overflow make it go to the correct level when it heats up). Unlike many other cars, it is quite important that the expansion tank is filled. At least on my car I have noticed significant temperature changes from a tank at the level you talked of to a filled up tank.
As far as coolants, they are interchangeable. It really doesn't matter if you mix and match (I try to stay away from those new extended life ones because they have a tendency to clog the rediator apparently, there is a lawsuit by general motors against the company or something because of this problem).
Put on the a/c and see if one fan comes on (only one is supposed to). Then let the car heat up and see if both of the fans come on. Both have to be blowing to keep the temperature down. If the fans don't come on, or only one comes on then that is your problem. If they are working then I would start going through your books and going over the cooling system. It might be the switch to engage the fans or an electrical problem (highly likely considering ferrari's electrical proficiency or lack thereof). I would start with the relays and fuses since they are easiest to access.
My car heats up to about 190 when it idles and the fans just keep it at that temperature, on a hot day they work to keep it at 195-200 when idling.
Hope some of this helps,
Bret |
irfgt
| | Posted on Sunday, January 14, 2001 - 8:14 pm: | |
Sounds like the radiator fans are not working. There should be a a switch with two wires in the bottom of the radiator. Pull the wires off the switch and temporarily connect them together and turn the ignition switch on. The fans should come on. If they do then you need a new switch. It is OK to mix the coolants as long as you do not use the new long life coolant which is orange. |
Rob Lay (Rob328gts)
| | Posted on Sunday, January 14, 2001 - 5:52 pm: | |
After letting it cool down, I noticed there was only about 2 inchs of coolant looking into the reservoir. Was this really bad? Or the coolant goes through the complete system and that is only the extra.
Well anyway, I still refilled to the suggested level with about 50% coolant and 50% water. Was this the correct thing to do? Was it ok to add coolant from a different manufacturer, with something different already in there?
Thanks |
Rob Lay (Rob328gts)
| | Posted on Sunday, January 14, 2001 - 4:02 pm: | |
it takes a good 5 minutes to warm the car up, but once warm it will only take another 5-10 minutes for the car to overheat and coolant come pouring out the overflow.
is this normal or is there something like an idle fan or something not working.
as soon as I got the car moving, even at low speeds, the temperature dropped like a rock back to normal.
thanks |
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