'87 760T lock/ABS fuse blowing

My brother has a 760 Turbo which started blowing the fuse for the power
locks and ABS system. At first he couldn't tell when it was blowing, it
would just randomly do it, sometimes after driving for days, sometimes
within hours. One day he heard it blow after unlocking (or locking?) the
doors, then today he put one in and it blew instantly. I'm suspecting a
chafed wire in the door lock system but does anyone have other ideas?

 

On an '87 I'm still thinking about crumbling wiring. That sort of shifts
suspicion to places where the wiring goes under the hood or anywhere outside
the cabin.

Mike

 

That's a thought, I certainly had to redo the engine harness on mine, I
haven't had any trouble with the lock or ABS wiring though, I don't think
much of it even goes under the hood since the ABS system is in the trunk of
the early cars.

 

Wagon or four-door? If a wagon, check the wiring bundle at the tailgate
hinge. That gets a lot of flexing. '87 and earlier 760s weren't known for
good insulation. I'd suspect a short there or at one of the other door
hinges. These shorts can be hard to find. there's a $20 gadget here --
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=94181 --
that might help. I haven't used it. If anyone has, I'd be interested to hear
how it worked.

Pete (fP)

 

It's a sedan, though I suppose it's worth checking the trunk lock wiring.

I actually have a nice Harris cable tracer, not sure how useful it would be
in a car though as the color codes are usually sufficient. I'm a little
curious how well the Harbor Freight one works since the cost is a fraction
of what I paid for mine.

 

The point of the cable tracer is that it will identify a short, ideally
through a bundle of other wires and maybe some panelling. The theory is that
you push a radio signal into the lead in question and run a tuned tracer
along its general direction. When the signal stops, you've (theoretically)
found the place where the signal jumps to ground. Of course, with an
intermittent short, you'd have be wiggling the right wires in the right way
and in the right place to get any sort of diagnostics out of it.

Pete