Malfunctioning tail/brake light

2001 TOYOTA TACOMA
170,000 MILES • 3.4L • V6 • 2WD • AUTOMATIC
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MATTJHEN
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My taillight (only one on side) is not working. The terminals on the bulb were melted, and I replaced that. Long story short, after some testing I narrowed it down to the wiring harness on the one side that is some how not connecting? All wires are connected though, and I scrubbed it free of any dirt/corrosion. I’m hoping there’s a fix other than taking to a mechanic to rewire or something?
Thanks for any help.
*Also my lower blinker light on the front end of the same side is missing, like cut off so wires are exposed, could this be the problem?
Aug 15, 2019 at 10:52 AM
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JACOBANDNICKOLAS
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Welcome to 2CarPros.

Since it is only one light, I have a few questions. First, which side of the truck is it and which bulb. Next, you indicated it was narrowed down to the wiring harness. Is there power at the harness you are referring to? If there is but it doesn't make it to the bulb, then there is a break in that wire at some point. On the other hand, it could be a corroded connection. Have you tried to wire direct and bypass the plug? Also, I know that aftermarket light sockets have different color wiring. Are you sure it is connected correctly?

Let me know which side and bulb so I can study a few wiring schematics to better help. I will watch for your reply.

Take care,
Joe
Aug 15, 2019 at 7:14 PM
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MATTJHEN
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I have not. That would be a good final thing to test as it would narrow it down to the actual connector or the wire itself. thank you. And it is the passenger rear side, the actual tail light.
Aug 17, 2019 at 4:24 PM
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JACOBANDNICKOLAS
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Welcome back:

Let me know what you find and we'll go from there.

Take care,
Joe
Aug 17, 2019 at 5:26 PM
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MATTJHEN
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Hey Joe,

So I bought a new terminal, I got from the junkyard and tried it out bypassing the actual wiring. It worked. Once I connected to the actual in wiring, it doesn’t. so I think I narrowed it to the actual wire itself, for the taillight. Which helps, but i don’t even know where i’d begin to look for that.
Aug 22, 2019 at 6:45 PM
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JACOBANDNICKOLAS
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Welcome back:

Confirm the ground to the light socket at the assembly is good. If it is, then start at the light assembly. Use your test light and follow the power wire back to where it worked. At some point, you will find a break in the wire. The wiring runs along the frame under the vehicle.

Let me know if that makes sense or if you have other questions.

Joe
Aug 22, 2019 at 9:44 PM