Paul,
Trouble shooting to find an electrical short can be a pain in the rear!
Thankfully a usefull trick on your pickup will also help roadster owners.
Take a blown fuse, and SOLDER to wires to the end of the fuse. Hook up
these wires to a good dual filament taillight/stop light bulb. One
wire is soldered to the two contacts on the bottom, and the other wire
is wrapped around the base of the bulp.
[NOTE: on later model cars with "spade" connector fuses, you can use a
dremel tool to grind away some of the plastic, enough to solder on the
connecting wires].
If you install the "fuse/bulb" into the fuse holder... the light will
be OFF if there is no short. A bright glow from the bulb will occur
if you have a short, or a load on the line.
So now that you have a visual indicator, you can start trouble shooting
the wiring.
Usually I find the shorts in places were the harness has been PINCHED
(seat, seat belt clamp down, etc) or passed through a firewall and no
rubber grommet.
On one harness I felt the short my running my hand up and down the
harness. It was shorted for "no reason" but I found a hot spot on the
harness. Unwrapping the harness, I discovered a unwrapped factory
ground splice that had cut into a hot wire. Odd failure (tail light
harness).
WARNING: That bulb will get hot enough to melt anything it is resting
against. Usually "hang the bulb" high enough you can see it, but allow
a few inches of air around it. I've melted a spot in my carpet, and also
in a rubber floot mat, in the past. It does get HOT. Still great to help
out locating the problem. (Also useful item to carry with your spares).
Cheers,
Tom Walter '68 2000
Austin, TX
>
>1987 V6 5 speed dually Nissan pickup. Can't keep a fuse in the fuel pump
>circuit! The pump will run all day when wired directly to a battery but
>instantly pops the fuse when run through the stock wiring. Any ideas where
>I should start looking for the short?
>
>TIA,
>Paul
>OROC
>
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