Console disassembly 1984 400i

Looking to change my non working A/C fan speed switch and “while I am there” clean up Etc.

Can anyone give me instructions as to how to disassemble the console?

Thank you
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https://www.ferrarichat.com/forum/threads/412-dash-removal.188183/
The early instructions posted on that post are for the older dashboard, but after a few posts you can see the procedure applicabel to 412 (400i Gen2).

 

Thank you very much for pointing me to this post.
I will get to working on my car today and report later.

Have a good holiday.

 

It was actual very simple process.
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After the gauge cluster is out, were there any screws to take out there? Other than the two under the ash tray, are there any other screws to remove? I never thought the center 'flat' piece would come out itself without the side pieces. Lots of wires and cables holding that piece in I am sure but for your job, you probably don't need to go further.
Ken
p.s. I suggest some graphite on the air flow control cables while you are in there!

 

While you're there, you should replace those two fan switches that are cheapie, incorrect units. And also the screws holding in your gauges shouldn't be little silver screws but black thumb knobs.

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Thanks for the photo, I didn’t know which were the correct buttons, in fact i saw a pair of the thumb type you mention in the trunk, i will make the change next weekend and will look for a pair of the correct toggle switches as well.

Additionally:
The reason I was in there is because my front A/C 3 speed fan switch is not working correctly and so I purchased a new one but to find that the problem is not the actual switch, my switch is good and I could not figure out the problem.

The fan works only when the switch is in-position 3 for high speed only.

Do you have any thoughts on this?

Thank you for your feedback.



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Not sure about 400i gen2, but on the gen1 there is a wire wound resistor bolted against the fan blower (on the left side of the gold/cadnium plated frame that appears on your 5th photo, 20cm under the clock). This resistor is what regulates the fan speed.

As your system works on the 3rd position I presume there is an issue with the resistor. (When you use the third position the resistor is bypassed)

 

bjwhite, You do show the correct fan switches for the heat / vent. Although if you find them they are not low price, they are "cheapie" and easily break.
Ken

 

My "cheapie" comment referred to the ones he has installed. Regarding replacements, they are extremely common switches used in all kinds of cars over the years. I believe I got my replacements from a British car supplier and you end up using the little square trim parts (I got new ones from Eurospares because mine were damaged) and the little square switch "knobs" fit right on. I remember the switches from a British parts house to be extremely cheap--$20 or so.

 

I understood your reference to cheapie switches but since the "correct" ones keep failing I consider them cheap. Glad to hear their are lower cost sources for them. (I bet the ones on the red console will last 50 years!)
Ken

 

Good day Raemin,

This is the same setup on the 365. The resistor is a power wire-wound resistor with a ceramic core. The resistor has "taps"/connections to it that create multiple resistances that ultimately are in series with the fan motor resulting is less voltage being fed the motor... and thus lowering its speed. It is an old design, that works, at the expense of dissipating a lot of heat across this resistor (hence why it is a ceramic power resistor) and a reduction in motor torque. There are better methods for controlling (DC) motor speed (e.g. PWM control), but does require a bit smarter controller. Why Ferrari went this route is odd, as the tech to create the better motor controller was certainly available at the time and would not have been costly (perhaps a few $$$ more than the resistor approach).

Anyway... you are quite right that the issue could very well be this power resistor. I would check the connections to this resistor and if all looks fine, then check the resistor's resistance. If it is very, very, high or infinite, then one of the windings has failed. If so then you can buy a replacement from an electrical supplier (Digikey, etc) for relatively low cost. If the original poster is unsure which would be a suitable replacement, then please post up and I will check mine and find a part number for you to order.

Cheers,

Sam

 

Back then I fixed my dashboard resistor with nichrome wire (available in most e-cigarette shop). Worked quite well. Spal "brushed" blowers do still use a resistor, so replacement should be easy to source.

I'd rather have a resistor here to be honest: a cheap PWM controller so close to the radio could cause lots of noise. Slow PWM pulses can also wear the commutator and brushes.

If you design a controller with a temp probe I would probably ask you for one though...

 

Good day Raemin,

You could try and repair the original resistor, but I do not think this is prudent or safe. Exposed nichrome wire must be use with caution, as it glows red hot and so anything in contact to it could ignite the surrounding materials. The original windings are ot designed to do this and are coated as well. Secondly, depending upon the amount of localized heat generated by the nichrome wire you could cause other issues including the reflow of solder if that is what you used to attach the nichrome wire. Thirdly, wire wound power resistors are readily available and are not very expensive... depending upon the resistance, size, and wattage they could be under $10 or so... Consequently it just makes sense to replace the power resistor.

As for a PWM controller... you must have been using some pretty nasty or archaic PWM controllers, as properly designed ones will have minimal radiated and conductive EMI effects on surrounding devices. As for commutator and brush wear... can you go into detail and/or explain why this would occur, as I have never come across this type of issue. I typically design with conducted and radiated emissions in mind and this involves ample use of filtering, ferrites, etc and to date my gear has not caused any issues. These days having electronics sing like a song bird will result in a knock at the door by the respective Federal Communication department... less, of course, you are some unknown manufacturer selling stuff on Ebay ...

Cheers,

Sam

 

Thank you very much for this information. I will dig in and look for the resistor.
I will post my findings.
I greatly appreciate the help of all of you guys.


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Hi Sam:
Thank you very much for taking the time to send your comments, invaluable to me.
I will check the resistor over the weekend and report accordingly. I hope this is the problem and can resolve soon.

Ricardo

 

Brian:
Are the seats of your car blue or red?
Or did you make an interior change?

 

Good evening:
Considering the super knowledgeable group that has shared input in this thread, I would would like to consult on another interesting issue my car has developed:

Suddenly the driver's side turn signal stopped working normally and now from inside the car you can hear the kicking sound super fast, the dash blinker indicator does not light up, the front turn signal light does not turn on while the rear light flashes intermittently very fast but very deem. The hazard lights operate normal all around four corners.

I have cleaned all bulbs, connectors and look for shorts but to no avail.

Any feedback and guidance would be great

Thank you.

 

One of the light does not provide enough resistance to the circuit, so either a bulb is damaged, or the ground is broken.

1) That's what would happen if you use LED bulbs.
2) Check if the problem is persistent regardless of right or left operation.
3) If there is a problem on the one side but not the other, I would look for a faulty ground on the front turn signals: the bulb holder are held by a "metallic cup". On the 365 this is the metallic part the grounds the bulb, while on later models there is an additional ground wire that is bolted together with the front spoiler next to the side marker repeaters. This circuit shares its ground together with the heater fans that obviously had a problem on your car (see the new toggle switches we've been talking about).
4) While you are there, check the side marker repeaters as they can collect a huge amount of mud (you can access these from the fender, the ground I am talking about is also there)
5) If both right/left are faulty I would inspect the relay box under the footwell. On the Gen2, this is a multi-layer unit that is prone to fail

 

*When you mention the use of LED bulbs (No 1) do you refer to LED bulbs anywhere in the car?
Reason I ask is that when I purchased the car the gauge cluster lights were very deem so while I was fixing the stereo head unit, I had the lightbulbs from the gauges replaced with LED's to achieve brighter ilumination.
Could this have caused the problem? There are no other LED bulbs in the car.

Over the weekend I will check all of your 5 points

Thank you for your advice
Ricardo

 

Indeed most PWM controllers from that era are nasty! See the Dinoplex under the hood...

In the past I've done quite a lot of radio controlled cars/planes, and once the ESC became the norm we all had to buy commutator lathe, expensive silver brushes and harder brush springs. The slow pulses of the pwm controllers were just "eating" the brush/coms. One could easily spot the sparks on the commutator, while the mechanical ESCs (resistor based) had no such issue. Needless to say that these ESCs were playing havoc with the AM radio we were using. Multiple fast switching FETs and capacitors somehow mitigated the issue.

I can understand why a 412 (400i gen2) owner would need a better controller as the AC can be "too cool" (dual evaporator, triple ASTI fan, bigger 210 compressor), so the resistor is used much more often and is more likely to fail. Given how hard it is to remove the AC fan from the dashboard, I would really avoid any unnecessary wear on this motor, so that's definitively a place were I would invest in a high quality PWM controller.

My smaller AC is running at full speed most of the time and has never been "too cool" so far.

 

Not my car. I just found a decent pic to show you. My seats are red (but my dash and center console is black)

 

Only the 6 turn signal bulbs are concerned.

Many of us are using LEDs in the instrument panels, no issue except that you cannot use the dimmer any-more, but who would like to dim the dashboard? The knob under the rpm counter is a dimmer for the dashboard, should be turned fully anti-clockwise when using LEDs.

 

Thank you


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Good day Raemin,

Understood. However, I am still unclear how the PWM knackered the motor prematurely unless the PWM controller was the worst ever. As for radiated noise/EMI... faster switching devices (e.g FETs, etc) would simply make it worst, as the fast signaling edge rates would introduce a lot more harmonics to the radiated EMI... This is one of the reasons why it is much harder to design new and faster gear to comply with Governmental regulations. If anything Caps would certainly filter and/or slow down the edge rates and so would mitigate EMI. These days one uses a number of components in addition to Caps (e.g. ferrites, inductors, shielding, etc) to contain EMI.

Cheers,

Sam