ManuFromParis

I have two 964 with cruise control, a '90 coupé and a '92 Targa.

The rear spoiler automatism on the Targa doesn't work. Spoiler warning light doesn't turn off after the first yards of move, as it should.
I can rise the spoiler manually though (center console's button).
Another symptom : the cruise control doesn't work on the Targa, but I haven't really looked into that since I guess the "speed info" shall likely be shared by both units.

It all works fine on the coupé (Spoiler Automatic Rise and Cruise Control)
So I exchanged the Speedometer and Rise Control Unit on both cars, first individually, then at the same time. But the symptoms remained the same whatever the exchange :
- Spoiler rises automatically on the coupé but not on the Targa.
- Speed is displayed on both cars.
- Spoiler light turns off only on the coupé.
- both manual commands works.

So I guess both speedometer and Rise Control Unit are working. Any other test I shall perform about these parts ?

On a friend's car, we solved the same issue with an added ground wire between the gear box and the body, as there are rumors about the Rise Control Unit being troubled while booting when the starter is used. So I added another ground wire on the targa, without success.

Any ideas ?

Goughary

Check on the one that you can raise and lower the spoiler manually, that the previous owner may have pulled two pins out of the spoiler control module. In early cars the module is under the passenger seat, later are up under the dash on the passenger foot well. Re-insert the two pins, and it'll work again.

It was a common upgrade for many.

ManuFromParis

I'm not sure I understand what you mean.
I've unfitted the spoiler control module on the Targa (faulty car) and opened it : it looks like the one which works (coupé).

The Control module from the coupé (good car) doesn't rise the spoiler on the Targa (faulty car), and the Control Unit from the Targa rises the spoiler on the coupé. So both Control Units are good.

Do you mean a pin from the control plug, on car's wire loom side ?

Goughary

A lot of guys have pulled two pins out of the plug that goes to the spoiler module. This disables the speed sensor and allows you to manually control the up down on the spoiler. Or rather, the only way to make the spoiler go up or down is then the manual control. So check the plug itself and verify if all the pins are there. Usually what they would do is simply take them out and tape them back, so they may be there on the loom and able to be reinserted.

ManuFromParis

I wonder why someone would do that since the manual button always operates, but I'll check that...

Any other lead to follow ?

Goughary

The reason is when you are stopping and starting the spoiler is constantly going up and down and this can be annoying - and causes wear on the mechanism. So for example, maybe you are in traffic and you just leave it down.
Or in my case (i haven't done the mod) - I'm in traffic in high temps in the summer for an hour at a time, would be nice to leave it up for added cooling- more heat can escape from the engine bay or more airflow at low speeds...

Anyway, take a look at yours. It's the first thing to look for if the spoiler functions as it should with the switch on the console but doesn't actuate on its own at 53mph

Mikke_Possu

I Replaced brake pedal microswitch (Part # 96461330100) and clutch microswitch (Part # 96461341500) cruise control start working again. Most likely clutch microswitch was broken but those are relative cheap so I changed both.

ManuFromParis

luft

ManuFromParis, and?

jayagopal50

plastic gear wheel gets worn quickly..after 10 years i have left it in UP POSITION.

luft

i am in the same position 10 days now, going to fix it soon. Its important not only up for down force and the cooling but for the looks i prefer the spoiler down, as the car looks better in my book.

C'mon ManuFromParis you ask a question for help and the nice people here on Rennlist try to help you and......?