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Car: 2003 996 Cab.


Symptom: The fuse for the front power windows and the fuse for the rear windows will blow instantly when a new fuse is inserted.


History: The car was in winter storage and, though disconnected, the battery went 100% flat. I reconnected the battery and used a jump-start box and she fired right up after letting the battery pick up a little charge. But the windows rolled themselves all the way down and then (I guessing here) the fuses blew. When I replace a fuse, it blows even before I can get it all the way seated.

Also, when I got the car home I removed the battery and put it on a slow charge, so the car was essentially without power for 2 days.

I've scanned the car with a Foxwell NT-510 and there are no faults in any system.


I don't have any idea where to start troubleshooting this. I don't know where to find a wiring diagram to begin knowing where to look. I'm handy with tools and comfortable with electricity, but this has me stumped.


Any thoughts on where to begin?

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If you can get a copy of the Bentley manual they have them also I had found them on line and had my son print and laminate them "he is a printer" . Now step

1.  remove the fuse and from the load side measure the resistance

2. remove the battery, don't want to damage meter

3. note the resistance. 

4. press each of the window switch's check the resistance for each note value

5. the lowest resistance is most likely the problem.

6 now try to find the part that is causing the low resistance.



1. place jumper wire or 100 amp fuse in fuse socket

2. run windows 

3 watch for smoke

4. put smoke back in

5 call insurance


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Thanks, @Ronnie38; I'll try the first steps first. (But I've checked my insurance, just in case I need to follow the Red Neck procedure.)  

Do you happen to know, on the 996 fuse block.... Is the upper leg of the fuse the power side, or the load side? (I guess I can figure this out with my Fluke, huh?)

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  • 2 weeks later...

Does some kind soul out there have access to the Bentley 996 book and would be willing to make me a copy of the wiring diagrams for the 996 Cabrio?

I've troubleshot this as far as my skills will take me, and I'm to the point where I'm in need of some better information.


Thanks in advance if you can help me figure out why both power window fuses on my 996 Cab blow in an instant.

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