Wiring problem

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Casey1104

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What would cause this issue when I hit the brakes my running lights come on and when the turn signal is left it makes the running lights blink.
 

kennythewelder

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You have a short between the left turn wire, and the running lights wires. green wire is right turn, yellow wire is left turn, and brown wire is running lights. The brake lights work off of the turn signal wires. So when you hit the brakes, both the yellow wire and the green wire become hot. When you put the turn signal on, left is on the same yellow wire as the left brake wire. Also the green wire becomes hot when you press the brakes, and just like the yellow wire, when you put the right turn signal on, the green wire becomes hot. Somewhere on your truck, the yellow wire, and the brown wire are touching. Not the outer coating on the wire, but the inside copper wire is toughing each other. It could be anywhere from the tail lights, to the trailer wire connector, to the steering column. You just have to start at one end, and work your way back to the other end. I would start at the tail lights. A test light is the rite tool for the job, but keep in mind that a short will feed the whole system.
 

Casey1104

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You have a short between the left turn wire, and the running lights wires. green wire is right turn, yellow wire is left turn, and brown wire is running lights. The brake lights work off of the turn signal wires. So when you hit the brakes, both the yellow wire and the green wire become hot. When you put the turn signal on, left is on the same yellow wire as the left brake wire. Also the green wire becomes hot when you press the brakes, and just like the yellow wire, when you put the right turn signal on, the green wire becomes hot. Somewhere on your truck, the yellow wire, and the brown wire are touching. Not the outer coating on the wire, but the inside copper wire is toughing each other. It could be anywhere from the tail lights, to the trailer wire connector, to the steering column. You just have to start at one end, and work your way back to the other end. I would start at the tail lights. A test light is the rite tool for the job, but keep in mind that a short will feed the whole system.
Okay thank you for the reply I got all led tail lights on my tuck I think I got an idea of where it's happening would the short have to be on the left side to make it do that or doesn't matter the side?
 

kennythewelder

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Well, the wiring that feeds the left side anyway. You could try unplugging things and see if it goes away. Start on the left side of course. I am sure it is the yellow left turn signal wire where the short is. Could be @ the LEDs IDK.
 

PlayingWithTBI

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Also make sure you have good grounds. With a floating ground, electricity will go through other devices to complete the circuit...
 

Casey1104

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Well, the wiring that feeds the left side anyway. You could try unplugging things and see if it goes away. Start on the left side of course. I am sure it is the yellow left turn signal wire where the short is. Could be @ the LEDs IDK.
I'm pretty sure it's the multifunction switch because I was playing around with that and it went away then came back when I switched over to the right side.
 
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