Mike J

Hi Flavien,

Do you mean a wire was partially cut under the main fuse box in the front of the car? I guess that would be the main supply line to the electronic controller that resides behind the rear seats. I might check that out this winter, my car has shown this problem but only a few times. Once though, the roof was fully open, and it was painfull to get it closed. If the current is limited by a cut wire, it can overheat the motors since they will not be able to draw the current they need to run at their proper speed.

Thanks for the comment!

Cheers,

Mike

ltc

Actually I would imagine it to be the reverse.

If the wire has a high resistance (due to mechanical damage/reduced number of strands), then it will produce a voltage drop (right up until the moment where it acts like a fuse due to I2T heating), thus allowing for less voltage to be applied to the motors; under such conditions, I can't see the motors overheating.

Unless of course Ohm was wrong and I will delete everything.

ltc

In this case, the simplest thing to do is simply put a voltmeter on the motor + lead when the Targa roof is operated.
Measure the voltage and you have your answer.

Mike J

Except is only happens for instance on my car say twice a year, and the motors and control unit are buried behind the rear seat panel and I usually do not pack a voltmeter in the trunk, so yes the idea is simple but not practical, at least for me.

If you have not experienced the situation, the motors that close the roof are laboring to close the roof and seem to be running about half speed. I can not believe that in that situation they are not warming up, given they are running as least twice as long as usual. I agree, its sounds like the motors are likely getting less voltage than they are specified for, and are running below their design speed.

Cheers,

Mike

Flav9xx

Hi MikeJ,

on my car, the damaged wire was located under the fusebox, on the right hand side of the car (close to the front trunk).

I guess that you must inspect the wire on their whole length, from the fuse box to the targa electrical motors. There may be a bad connection or damaged wire somewhere.
Not an easy problem to solve..

Good luck

Flavien

Leanit

Thanks for the tip, Flavien. I'll check it out.

- Matt