Porsche 964 central locking unit

[Pete RS]

I have just got my 1989 964 home for the first time and it has a selection of electrical issues:

Rear spoiler not working - either at speed or from the central switch
Central locking not working - neither by key or from button on central console
Blower not working - think this one is a blown fuse in the engine compartment
Electric seats not working

Car runs and drives fine though

The car has not been used for ages, I bought it as a project and so I'm not cross about these issues.

However, can anyone tell me where to find the central locking control unit please? Is it under the dash or in the luggage compartment or under the passenger seat. I believe I have a damp problem in the foot well which may be contibuting to these issues but need to start with this central locking issue

Thanks
Pete

[PTT]

There is a relay in the passenger footwell.
PORSCHE 911 CENTRAL LOCKING RELAY 3.2 911.618.113.01

[Pete RS]

PTT said:

There is a relay in the passenger footwell.
PORSCHE 911 CENTRAL LOCKING RELAY 3.2 911.618.113.01

ok thanks I will take a look

[shoestring7]

I experienced a series of electrical issues with my 964 inc. heater blower and mirrors. Fixed when one of the main loom plugs behind the dash was plugged back in......

SS7

[Pete RS]

shoestring7 said:

I experienced a series of electrical issues with my 964 inc. heater blower and mirrors. Fixed when one of the main loom plugs behind the dash was plugged back in......

SS7

I would not be surprised about a similar problem with this car.

I found water in the relay mentioned above, dried it out but have not got it working as yet. However, IO did manage to get the blower fan and radio working again before I ran out of light. I think I have a wiring issue under the dash where power is taken to the back of the vehicle as the rear wiper is also not working along with the spoiler.

Just need to get a circuit diagram and trace the wires and I'm sure it will be something like a plug hanging out to sort some of the issues and probably a duff relay for other items. Patience will be the key I think

[N24]

The spoiler control box is under the drivers seat - grey box. Worth a check, clean up contacts.

[Pete RS]

N24 said:

The spoiler control box is under the drivers seat - grey box. Worth a check, clean up contacts.

Thanks will take a look.

I have since found water in the rear footwell on the passenger side and so am now thinking the best idea is to take both seats out, dry everything out and then go through and check all the connections sitting under the two front seats.

Clearly, I hope I'm also going to find where the water came from in the first place.

Thanks again

P

[shoestring7]

Pete RS said:

N24 said:

The spoiler control box is under the drivers seat - grey box. Worth a check, clean up contacts.

Thanks will take a look.

I have since found water in the rear footwell on the passenger side and so am now thinking the best idea is to take both seats out, dry everything out and then go through and check all the connections sitting under the two front seats.

Clearly, I hope I'm also going to find where the water came from in the first place.

Thanks again

P

Check sunroof drain tubes and any signs of perishing in the rear screen seal.

SS7

[boxsey]

Pete RS said:

hanks will take a look.

I have since found water in the rear footwell on the passenger side and so am now thinking the best idea is to take both seats out, dry everything out and then go through and check all the connections sitting under the two front seats.

Clearly, I hope I'm also going to find where the water came from in the first place.

Thanks again

P

I had that. Found buckets of water under the seat pads when I stripped out the soundproofing. The culprits were the rubber seals on the rear window quarters. I had these replaced for the 993 seals (which is a popular upgrade on 964s).

[Pete RS]

Thanks for the suggestions on the leaks - the rear quarters idea fits with some other signs of water ingress.

Cheers
P

[Warmfuzzies]

Spoiler module can be passenger footwell just under dash, small 3-4 inch box.
ABS working ok? I think it uses this for speed control. Does yours have the manual up down control?? Early ones don't have the same functionality

Do you have a sunroof? Drain tubes can cause issues.


Kevin.

[ras62]

Worth checking Relays 11 & 33 are working as they affect many of the systems you mention.

[Pete RS]

Thanks for the suggestions.

I have ripped a load of the sound insulation out of the car, the seats are now in the conservatory, and the car is looking a bit sorry for itself. I just had to get the water out before I did anything else.

So I have located the three spoiler control boxes/ relays. The grey box plus relay under the seat and the main control unit under the dash. I have now invested in a 12v power supply so I'm going to power up bits of the car independently to see if I can check sub systems. I'm pretty convinced I have wiring issues under the dash though - the reason being that we had permanent 12v to the spoiler and it was unplugged in the engine compartment. Since taking the sound proofing out the 12v has disappeared.

In answer to the question about the manual control for the spoiler - yes I do have the manual control in the centre console.

The electric mirrors are now working though and there was no rot in the pan when I got the sound proofing out.

Just wish the weather was better to allow more progress

[ray stobbs]

you might want to try and manuely rise and close the spoiler by disconecting the gearbox from the motor on the engine lid use a battery drill to turn the cable the gear box has a bearing that seises cable just pulls out of motor and has a square end on it

[Pete RS]

ray stobbs said:

you might want to try and manuely rise and close the spoiler by disconecting the gearbox from the motor on the engine lid use a battery drill to turn the cable the gear box has a bearing that seises cable just pulls out of motor and has a square end on it

thanks Ray.

I defo have a wiring problem. Just had the spoiler control unit checked out but the problem is between there and the spoiler. Think I'm pretty close to sorting it now as I have a wiring diagram thanks to another member on here