Buildingadrm964

I just bought a 1991 964 and the rear spoiler light is always on. I thought I would ask the question here, before I spent a few hours in the driveway trying to fix it. Any input? Is it simply a micro switch?

John McM

Could be microswitches, controller unit and/or the speed input.

Does the spoiler operate normally?
Do the manual switches work correctly?
Any glitches with the speedometer reading?

lastly, where are you located?

John McM

More reading on this thread https://rennlist.com/forums/964-foru...r-spoiler.html

Buildingadrm964

The spoiler operates normally.
The manual switch works to put it up and down.
There are no glitches in the speedometer.

I am located in Toronto, Canada, but the car was purchased in Boston, so it is a US origin car.

Not it sure if this is relevant, but the car is a cab.

John McM

It is possible that one or more of the microswitches is not working, but it's more likely the controller. The warning light should be on when the ignition is first turned on, but should extinguish when the car reaches ~ 4 mph, if it's getting a speed signal. The speedo and normal operation indicate it's getting a speed signal.

From here, you could find another 964, swap its controller to your car and see if it extinguishes the light. If it does then you know your controller needs repairing.

If that's not practical, then you could send the controller away for repair or if you have a general electrical repair shop near you, you could get them to replace the warning signal transistor. It's a common BC337. The position is in the pic.

Buildingadrm964

I actually have another 964, so I will try to swap it out and see if that solves the problem.

John McM

Perfect solution. 1991 seems to be the changeover year for the unit location. In the RHD cars it’s either under the right hand seat or under the left hand dash.