944 Cab Roof

[seventh-heaven]

Trying to fix a 944 Cab electric roof for a friend. If you know the circuit you will know that there is a control module that is what controls when you can open and close the roof - I think the primary restriction is the speed (or lack there of). If I bypass the module with +12v and an earth it all works properly including the limit switches - but not when supplied through the module.

The module has 12v to it and a good earth, but I can find no information about what the module is looking for to give it the right conditions to release the supply to the roof.

I am making an assumption that it is not a defective module as friend had already changed that with no success.

Any insight or info would be appreciated.

Thanks

[A9XXC]

Try on Porscheclubukforum - dont need to be a club member, just usual sign up stuff.

[pauljmcnulty]

seventh-heaven said:

I am making an assumption that it is not a defective module as friend had already changed that with no success.

Just a thought, if you've narrowed it down to the module are you sure the replacement was any good? It's not unusual for breakers to send out parts that might not be working. I guess a new one might be worth trying, sometimes Porsche parts are surprisingly cheap. If it's wickedly expensive then finding another local owner who'd let you swap them over might be an idea.

[seventh-heaven]

£300 apparently!! That's why I was hoping someone might know the logic so that I can test it properly!

What I haven't understood yet is why there is a connection to the speedo and a Separate Hall sensor.

Does anyone have a workshop manual that describes the logic?

[poo at Paul's]

What are the symptoms, doesn't open or won't close?

If it won't open, it may well be the micro switches on the top windscreen pillar lugs. These stick and think the roof is still clamped down even when released so won't operate the motors.

My one had no speed module, it needed the ignition switch in pos one, ie motor off, to operate.

The microswitches in the windscreen top clamps were the only problem I ever had with my roof tbh, and it was 22 yr old

[seventh-heaven]

Thanks - as stated in origonal post it all works fine including all limit switches and the windscreen switches if fed with a false 12v feed and earth - only the control module that is the problem. However I have picked up elsewhere about the position 1 condition and in particular that this can be troublesome if the key switch barrel is worn.