964 C4 Cab some roof help needed

[Adrian W]

Hello chaps, I’ve had a look back about 20 pages and cant find anything, the search is still broken, A work colleague desperately needs some help, he Has a 964 cab, the roof has started playing up, it has been with an independent who has called in an auto electrician but still no joy, from what my colleague tells me I have little confidence that they know what they are doing.

The fault is when you try to lower the roof it unlocks, lifts about two inches and then lowers and locks itself. The indicator lamp stays Red all of the time even when locked.

They have fitted a new control unit,
Replaced both drive cables
Replaced both micro switches on the drivers side.
Replaced dash switch.
Checked latch micro switches


Any help or advice would be very gratefully received

[stuttgartmetal]

I had an Audi Cab that had a similar problem.
I posted and searched for a roof expert to no avail.
May well be adjustment, or bent frame that geometrically locks it up.
Could also be a friction issue.
Electric cab roofs, good when they work.
A mare when they dont.

[gtphile]

It does sound as though one or both the latch microswitches are playing up, how have they tested it?

I had a 993 in which was doing exactly the same thing that was sorted with 2 new unlocking latches

[Adrian W]

gtphile said:

It does sound as though one or both the latch microswitches are playing up, how have they tested it?

I had a 993 in which was doing exactly the same thing that was sorted with 2 new unlocking latches

I don't know, i'll check but im assuming they buzzed them out

[gtphile]

There is also a wiring loom which runs to the latches which can be damaged over time by opening and closing of the roof.

Think it runs up the o/s, but don't quote me on it!