82 911SC - short in backup light circuit
 

Backup lights repeatedly blow the 16 amp fuse in short order. The fuse does not blow right away but will usually do so easily within a day or so.

I've removed and troubleshot both rear light enclosures. They both look fine. I've also checked the switch at transmission. It looks OK also.


30+ years experience as instrument and controls tech at major power generation station and I can't figure this out! How embarrassing!

Anyway does anyone have any experience with this? Any possible "pinch" points or sharp edges in the wiring run that might be grounding the circuit?

Also I put a temp fuse on the wire to trans switch as flasher relay is on same fuse and I wanted to eliminate the relay circuit as a possible cause. Only the fuse in holder blows.

You could check the T14 plug ,T14/5 is power to switch, T14/6 is coming back from it.Then disconnect the T6a (right light) and T6/b (left light) to see as close as possible where could be the root of the problem?
[IMG]<a href="http://img255.imagevenue.com/img.php?image=49091_Backlight_thread_122_112lo.JPG " target=_blank><img src="http://img255.imagevenue.com/loc112/th_49091_Backlight_thread_122_112lo.JPG" border="0"></a>[/IMG]
One month ago I experienced the same problem ,it was the contact between the lamp and the socket which step by step moved to ground,very difficult to find that!!!
Cheer's up
JM

Thanks
 

I'll give it a try.