Damn gramlins

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Buck_77

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buck
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1974
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gmc jimmy
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350
Help me get rid of my electrical gremlins. (74 Jimmy )
so a couple weeks ago my hazards came on, apparently my hazard button is broke? So I pulled the hazards fuse, that kinda fixed that problem. But it got me looking and I noticed that when I apply the brakes my front left turn signal come on. Not the left and not blinking. Any of y’all got any suggestions? I believe the rear lights are all functioning properly.
 

crpntr78

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Go around the whole vehicle and clean every ground wire you can find. Several by the emergency brake pedal, several on the core support, passenger side engine head to body, battery to frame to name a few.
 

Turbo4whl

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Yes, could be a ground problem. Since you stated the hazard is broken, I would start there first. The The turn/hazard switch receives power from 3 different sources. 1) Hot all the time from the hazard flasher. 2) Feed from the ignition switch through the turn flasher. 3) Feed from the brake switch.

The switch, conveniently located under the steering wheel, is made of plastic. Old plastic gets brittle and breaks apart. Power can start to supply the wrong lamp wire.
 

SirRobyn0

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Fix the hazard switch issue first, turbo4whl, has given you great advice on how that works.

For the left signal coming on when you apply the brake the first thing I would look at is the socket on the left rear, you may have a cross bleed issue, from terminals touching in the socket or a bulb that has been forcibly installed the wrong way. If that all checks out look that the ground for that socket, electricity wants to find a path to ground and if the LF ground is bad, it my cross bleed to the signal where it finds grounds at the other sockets. If none of that fixes it then fan out to other connections and grounds, but I doubt you'll have to. It's usually in the socket or ground.
 

86 SCOTTSDALE

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A broken filament inside the left rear bulb will cause the same problem if the two filaments are touching.
 

Buck_77

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Thanks for the help guys. Hopefully I can find time this week to dig into it.
 

Buck_77

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Finally got around to messing with this. I had a burnt out bulb front right turn sig. replaced that, checked the grounds at all 4 light housing locations( good and cleaned). But I still get the front turn signals lighting up when I hit the brakes?
I’m not for sure but I think my turn signal switch is bad, the hazards won’t shut off, so I’ve got that fuse pulled.
Could that be a reason for the brake ‘light communication?
Gonna try to find a signal switch locally and see if that helps?

ideas??
 

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