Sten

Since the sun has broken through, I thought I'd fix my sunroof - it hasn't worked since I bought the car. Checked all fuses and the sunroof relay first, nothing obviuosly wrong. Pressing the switch had no effect, so I popped the switch out - the feed to the motor has been 'cut and shut', presumably for the original full closure alarm. Following the wiring through to the luggage compartment, I found a couple of 'black boxes' that must be the alarm system fitted to the original UK cars. I disconnected the relevant plug, and put +12V and earth from a bench supply onto the wires that lead back to the sunroof motor. The motor runs (and runs the other way when the polarity is reversed) but the sunroof doesn't move. I made two shorting leads to bypass the alarm. Into the back of the car, unzip the headlining to examine the motor/mechanism. I managed to find the emergency handle, and the sunroof opens and closes OK manually. Took the handle off, pressed the button and you can see the motor coupling spinning but no movement from the roof. Removed the 'gearbox' off the coupling, and I can grip the gear that moves the sunroof cables whilst turning the coupling shaft. The 'gearbox' doesn't look like it's meant to come apart. So... does the mechanism have a clutch fitted, or is it more likely that I have some stripped teeth and I'll have to replace it?

Barry

Adrian

Dear Barry,
Good troubleshooting well done. Unfortunately the clutch is part of the motor/transmission assembly.
Yes the do come apart but getting the parts you need might be a problem.
I would try one of the wreckers and see if they have any certified spares at second hand prices available.
Why would the sunroof be disabled for an alarm system? I suspect it was disabled before a sale onwards. Maybe to you or the owner before you. This is getting so damned common nowadays.
Ciao,
Adrian.

Sten

Adrian,
I don't think the sunroof was diasabled on purpose - more likely that the alarm is faulty. Having prised the box apart, it looks like the sunroof feed passes through a set of normally closed relay contacts so the sunroof works through the switch as normal. There's another relay in the path, I think this one would apply voltage to the motor to close the roof when you lock the car with the key fob. Looks like I'll be calling the breakers tomorrow...

Barry

Adrian

Dear Barry,
None of that alarm system is Porsche so I cannot be of much help to you. The original alarm system installed in the 89 C4 is the old 928 system. Very simple and quite reliable but never met UK insurance company requirements.
Ciao,
Adrian.

Sten

I was in the garage today having my new suspension fitted, and it turns out that the 'clutch' on the sunroof is adjusted by tightening the screw you remove to fit the manual winder - nipped it up and Voila! a fully functioning sunroof. Now it's going to rain for forty days and nights....

Barry

Sten

It's an old thread, and I've since had to bypass the control box that closes the windows and sunroof when you lock the car. If your Sunroof stops working and you have the original Hamilton&Palmer alarm system, try this:-

Rmove the carpet under the bonnet, look for a piece of wiring loom that passes in front of the Central Electric (Fuse) box and follow it down to the void above the master cylinder. Pull out the two black plastic boxes on the end of the loom, and remove the plug that has Blue, Yellow, White, Green and Red/White wires. Make up two shorting links and connect Blue to Yellow, then White to Green. Hopefully your Sunroof will now function..

time666

Barry that’s much appreciated mate and thanks for your time to take this pic.

I will have a go at this fix this weekend, be nice to get the sunroof working again, and I’m pretty sure it’s the dealer fitted Hamilton palmer sunroof module that’s caused the loss of signal between my interior switch and the rear sunroof motor.

My alarm doesn’t seem to work anyway at the moment so planning to replace the alarm soon. Do you think the standard alarm on 1990 model was completely removed and these Hamilton palmer ones put in their place?

Anyway I will let you know how I got on this weekend.

Cheers
Tim

time666

Barry,

Just to let you know i linked out the wires you suggested and I now have one fully operational sunroof again!

Must have lost one of the relays through the NC contact same as you, I had continuity through one cable from switch to sunroof, but lost the other.

Dont suppose you could let me know what wires are linked out on the central locking module too, just in case that fails in the future?

I owe you one, thanks. Looking forward to summer again now!

Tim

Mc.Queen 964

Time666, sorry for the off-topic, but I've got a Montecarlo S2 to!

Regards.