A/C Fan Switch

Yike! If the switch is still working there must be a way to build the plastic back up. JB Weld? Epoxy? You’ve got nothing to lose since you can find a (expensive) replacement if rebuilding material fails.

To be clear, I am not suggesting you glue the knob onto the stalk; just wondering if you can rebuild the stock with a hard glue then replace the knob.

 

I agree with trying some JB weld to build up the plastic. I would drill a small hole or two in the bad part of the plastic and insert something like a small nail (brad) to give a stronger purchase for the JB weld. When the JB is cured, sand the shaft/JBweld/brads to accept the knob.

As an aside... I would think there is nothing special about that rheostat and a replacement could be found at a supplier like McMaster Carr, etc. It doesn't matter what it looks like below the console.

 

I agree with Mike - I doubt there's much special about that part. Pull it out and find someone who knows electronics. I doubt McMaster, but Newark or something like that will have something.
20 years ago this part would have been on a peg at your local Radio Shack.

 

The AC blower switch is more than merely a rheostat. It also causes the AC clutch to engage. There are 4 leads that come off it.

 

Yes, it's an on/off switch as well as a rheostat but again, I can't believe there isn't a suitable replacement available. But if not, a two-pole would work if a small relay was incorporated to handle the load of the compressor clutch. It's all under the console so wouldn't matter appearance-wise.

That being said, I'd certainly try to repair the existing switch with JB weld or something similar and only if that failed would I try to find a replacement switch, etc. If it's felt that just applying JBWeld/filing/sanding to shape might not be strong enough, another option would be to cut off the plastic shaft several mm above the metal part of the switch and cut/file a step in the end of what's left of the shaft. Then get a piece of the same diameter plastic (or metal) rod, cut a corresponding step in the rod so that it mates with the step in the shaft, thus extending the shaft to the necessary length. Drill a small hole through the steps, put some JB Weld on the joining surfaces and insert a pin through the hole. After JB sets - do the necessary sanding/filing so the knob fits.

 

I own a 308 but I checked photos on the internet and it looks to me like the top cover holding the switches on a 328 can be removed without removing the console itself. The 308 has that sort of panel and the 328’s just looks bigger.

 

In the 328, the switch panel is held down by screws in holding the ashtray in place. once you take those out the whole thing lifts out. Its been a long while since I had mine apart... I think the switches are held in place by collar screws under the black switch plates its easy to get out, just don't bend the switch cover. As for the switch itself, the knob is held on with a tiny set screw - I'd file the top flat and get a longer set screw vs. JBweld etc.. OR file, and glue in a smaller screw so that your stock set screw can make contact. Be very careful of the plastic covers, they have small indents that grab the leather and can be easily broken. if that happens you end up with switch plates that rotate. The switch plates with the blue are not available anywhere... I think the one with fan speed is easy to find.. but $$$$

 

you don't have to remove seats or the center console to get the switches out. taking the center console out is easy - the wiring is confusing. If you do be very careful of the edges of the LED switches, they are brittle and can be easily cracked / broken... these are super hard to find and $$$$$$$ when you do.

 

A pot with an on/off switch built-in is super common. I don't know the specs of the Ferrari switch, but here's an example.
https://www.jameco.com/z/RV24A02F-10-15S1-B500K-Taiwan-Alpha-1-2-Watt-24mm-0-59-Inch-Shaft-500K-Ohm-Linear-Taper-Potentiometer-with-SPDT-Switch_2268671.html

Probably the Ferrari switch says right on the back the full scale resistance, if it's linear or log taper. You'd need to know the shaft diameter, that's easy.

 

That's not a knob -- it's a quarter-turn (or maybe half-turn) cover that holds a small 1A fuse. If yours is still working electrically = the fuse is OK, and you should invest whatever it takes to restore that shaft end form (doesn't look like it would be that difficult to me) -- see below.

Unfortunately, F doesn't show the internal schematic of the components/ECUs on their schematics. My guess would be that it would be very similar inside to the earlier TR fan speed ECUs that have 6 wires like yours (as both use the same common-emitter power transistor scheme for variable speed operation and closing a relay for full speed operation). On the later TR, they went to the 140151 that has fewer (4) wires, but that was more because they simplified the downstream wiring architecture (not because they changed what was basically inside the fan speed ECU). Here you can see the ridiculous complexity of what's inside 140151:

https://www.ferrarichat.com/forum/threads/ferrari-testarossa-blower-fan-speed-controller-50009003.665668/#post-148750453

but I don't know if they are identical. (It does seem way more complicated than what it needs to be to function to me, but I'm just happy when mine works ).

 

Forgot to add that maybe Oddparts (as referenced in that other thread) could help you with the shaft repair, if needed.

 

I just did a quick search. Un believable! I did see some staggering prices.

Re-originals?? Gt Car Parts?? T Rutlands?? Algar?? Ferrari of Denver?? Those last two dealer sources have amazed me with their NOS supplies of odd interior bits. Also, the prices were not terrible (relatively).

Good luck!

 

"Here you can see the ridiculous complexity of what's inside 140151:"

WOW! Clearly the philosophy of: "Why use ONE component to do a job when we can use EIGHT?" Can't think why all that circuitry is necessary to simply turn on/regulate the speed of a motor. FWIW, I first ran into that philosophy working on a Mercedes...

In any case, I'm confident the shaft on the switch in question can be repaired to operate as new using JB Weld and (possibly) an additional piece of plastic/metal rod.

 

Holey moley, that's not what I was expecting. There's a lot going on. Yes, the basis is a pot with a switch as I suggested, but there's a lot of extra stuff on top of that. Ok, yes, now I'm in the camp of trying to fix the shaft somehow. It's at least worth a shot. Only after that would I attempt to try to replace the pot. Last resort I have no doubt this could all be recreated with off-the-shelf individual parts, but it would be a project and probably not very pretty. Hopefully the guy on the Testarossa thread is serious about making replacements. Also interesting to note that the TR version seems to have a metal shaft, and I'm sure you see the advantage there!

 

I believe Ferrari's only defense is that it was probably the HVAC Vendor's design . I haven't studied the 6-wire version as much as the 4-wire version, but AFAIK, it just supplies a variable small variable current in the b-e leg of the power transistor to do the variable speed fan motor operation and then closes the relay when put to full speed in the hope that that would save the power transistor from baking to death, but the human nature of not setting things to full speed in the thought that using 3/4 or 7/8 speed was less-stressful on things worked against that and promoted cooking the power transistor -- which happens a lot (best IMO to use variable speed for 0 to 1/2 speed and then just go to maximum, to use the relay for the big motor current, if you want more airflow).

 

It's really the inside that makes the difference. Are the switches illuminated (I've never sat in a 328)? I think if you cracked the black box open, it's going to look rather simple to replace the pot.

 

Yes they are illuminated, should be able to get inside this like the heater control units?

 

You should try the parts dealers mentioned above, and also call Ferr Parts 916 974 1939 . Ive been buying parts from them for many years, sometimes Ferrari released bulletins that I believe show discontinued parts which are now available, that is what happened when I bought brand new rear Konis for my 89 328. Or , just take it in the ass and buy one thats on EbaY lol .

Big G

 

ASSUMING there is nothing wrong with the function of the switch, I would repair the shaft! With the switch out of the console, it would take maybe an hour's worth of work to do any one of several possible repair techniques. Seems way over-the-top to me to purchase another switch if the only issue is the damage shown in the pics.

OTOH, do whatever YOU are comfortable with. If that means finding an OEM replacement switch, then do that!

 

My BMW windshield squirter quit. I thought - $40-60 little pump assuming it's not just a fuse...w r o n g !! The pump is not getting juice and it looks like it's wired through the ECU. I give up, the car never had that feature as far as I'm concerned!

Might there be a way to take an elegant step backward? Wire up the fan like the basic 308's and just use the 328 fascia and knob? If that's too much of a step backward, perhaps find another motor control unit?