Who understands wiring diagram???

Bernie Benz b.benz at charter.net
Wed Jun 23 22:58:52 EDT 2004

> From: Kneale Brownson <knotnook at traverse.com>
> I have a circumstance where I blew the 5 amp fuse for the left running
> lights trying to set up for wiring for a trailer (with a relay device that
> takes power from the battery).  Replaced the fuse and no power to the left
> running lights circuit.
> So I'm following Tony Hoffman's advice that the circuit goes back to the
> headlights switch and there may be a problem either with the switch or
> somewhere else in the wiring.  Anyway, at the switch, there are two wires
> that get powered when the headlight switch is set to the first notch (tail
> and front marker lights), one is solid gray and the other is a green/black.
> Since the left rear tail light is a gray/black wire, I presume it starts
> from the headlights switch as the solid gray one and the right is the
> green/black, but I can't tell from trying to read the wiring diagram.
> I have a headlights side of the combo switch that I swapped out of our V8
> (same device), and when I check it out with the ohm meter, the two posts
> that "light up" when the headlight switch is first activated are the top
> outer post and the third down from the top inner.  Those are, respectively,
> the gray and the green/black wires in the harness.
> I have a spare bit of headlights switch harness that I plugged into the
> switch on the car and powered up (either of the big red wires) with the ohm
> meter to find that both the gray and the green/black wires are turned on by
> the running lights position of the switch.
> So I presume my switch is OK and I have a failure somewhere else in the
> wiring that's making the left running lights circuit nonfunctional.
> Since I want to use the left side as the source for my trailer tail lights,
> and since I apparently can't use the existing wires, I'd like to tap into
> the switch harness and run a wire to a relay and then out to the left tail
> light.  I'd make the wire from the relay 14 gauge or 12 gauge and have it
> provide power to the tail light wire in the trunk and to the harness for
> the trailer.  I'd power the relay from the fused battery source (12 gauge)
> for the relay unit that works with the brake/flasher lights.
> Can anyone tell me which wire (solid gray or green/black) at the headlights
> switch is for the left side?
> And does the rest of the plan sound reasonable?
No!  Find the problem and DFI if IAB, nor try to circumvent the problem.


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