wierd electrical short
#1
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wierd electrical short
My 94 pickup has a wierd electric problem, the brake lights are linked to the running lights. When I step on the brake, the front marker lights and the dash lights come on with the brake light. If I turn the headlight switch on the lights come on and so do the brake lights, and it wont let me set cruise control unless I turn the lights off. I know it has to be a short somewhere, has anyone had this problem before? Are there any logical places to look? I am not really wanting to tear the entire dash off, but looking like my only option.
#3
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At least one set of your lights do not have a ground so the current goes through a different set of bulbs (which lights them up as well) in order to light up.
I'd check the bulbs in the taillights first. If they're in the socket incorrectly (180*) or if it's the wrong bulb it will cause that problem. Next I would check the tail light plug to see if it has a ground with both taillight housings disconnected, if it does plug the housings back in and check the ground on the actual bulb sockets. A trailer light converter is also a possible culprit.
I'd check the bulbs in the taillights first. If they're in the socket incorrectly (180*) or if it's the wrong bulb it will cause that problem. Next I would check the tail light plug to see if it has a ground with both taillight housings disconnected, if it does plug the housings back in and check the ground on the actual bulb sockets. A trailer light converter is also a possible culprit.
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After a little more research I am suspecting the trailer plug in, mine has been converted to a flat 4 plug with very sketchy looking wiring. Will go check on it tonight
#5
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If you can't find a wiring or relay issue, I had my fuse box short, so I know that's a possibility. I don't have cruise control though but my brake lights were all funny.
Silly question, but did you check your fuses? That could be a clue if there's a short.
Silly question, but did you check your fuses? That could be a clue if there's a short.
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Yes the fuses were good, but the PO had a 30 amp fuse in there, which is a little scary. I fixed the issue, I pulled the rear lights and spend some time with a volt meter. There are 3 wires on the back of the brake light bulb, and I cut the plain green one. for whatever reason it had power when I turn on the headlights. works on one filament now.
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