Brake Lights/Blinker issue identification (1 Viewer)

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Joined
Nov 4, 2010
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Location
Atlanta, GA
IH8MUD Team,

My 76 FJ40 (completely re-wired about 2 years ago) started having the below issues recently, I believe simultaneously and all of a sudden. Wondering if you can suggest where I begin looking to identify the issue as I assume they are all related. REALLY don't want to take it to ACC (as much as I LOVE them) if I can find the issue myself. But, wiring makes me NERVOUS - almost burned up a truck once :p.

Advice and suggestions greatly appreciated!

Issues:
Front right blinker not working
Back left brake light not working
Right blinker dash indicator coming on intermittently when I press brake pedal
Back right blinker and red light are very dim/both will blink when right blinker is on and/or both will go out intermittently
 
Sounds like a ground issue.
 
I would start with the lights. If you are getting power to the light and the bulb is good then it is probably a ground that is not completing the circuit, but it could be another light within the circuit. Clean the ground connections. Start with the lights that are acting up, but it may not be those lights in question. Every light housing is either grounded by being attached to the frame or body or by a wire, depending by the year. Clean these connections. When lights operate strangely like you describe it is usually a ground. Then they're actual grounds coming off the wiring harness too. Those would be a white wire with a black stripe.
 
I would start with the lights. If you are getting power to the light and the bulb is good then it is probably a ground that is not completing the circuit, but it could be another light within the circuit. Clean the ground connections. Start with the lights that are acting up, but it may not be those lights in question. Every light housing is either grounded by being attached to the frame or body or by a wire, depending by the year. Clean these connections. When lights operate strangely like you describe it is usually a ground. Then they're actual grounds coming off the wiring harness too. Those would be a white wire with a black stripe.
Very helpful and gives me my next steps to take. Thx for that!!
 
Update: cleaned up some wiring and grounded each light at the housing but the primary issue was that my tail light housing was not holding the bulbs securely and that was creating my grounding issues.

Lesson: buy good housing - I replaced with OEM housing and things seem to be working solid now.
 

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