Taillight wiring issues
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4th Gear
Joined: Aug 2025
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Taillight wiring issues
My passenger side rear tail light does nothing with a right signal or brake but is fully bright when the lights are on.
I just inherited this truck so I know nothing about the wiring but the bulbs have all been replaced with LEDs if that makes a difference.
If anyone has any ideas where to start looking it would be super appreciated.
I just inherited this truck so I know nothing about the wiring but the bulbs have all been replaced with LEDs if that makes a difference.
If anyone has any ideas where to start looking it would be super appreciated.
Lead Driver
Joined: Jul 2017
Posts: 9,609
Likes: 1,179
From: San Jose, CA
LEDs can be polarity sensitive. If it’s a standard bulb base, try flipping it around. Although if it’s keyed, then that might not be possible. Check to make sure both housings are well grounded, however. Or yours, the standard style with a metal bucket and a plastic lens? Or are the LEDs complete modules?
Thread Starter
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4th Gear
Joined: Aug 2025
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Thanks for the help.
I had thought about the polarity issue but my understanding was that LEDs won't do anything if they are wired backwards. These do light up when the lights are on but they are bright, like if the brakes were pressed.
They are keyed bulbs so I am going to get some regular bulbs to test with.
I have the metal buckets that ground to the body.
Ian
I had thought about the polarity issue but my understanding was that LEDs won't do anything if they are wired backwards. These do light up when the lights are on but they are bright, like if the brakes were pressed.
They are keyed bulbs so I am going to get some regular bulbs to test with.
I have the metal buckets that ground to the body.
Ian
5th Wheeling
Joined: Jun 2025
Posts: 43
Likes: 13
Thanks for the help.
I had thought about the polarity issue but my understanding was that LEDs won't do anything if they are wired backwards. These do light up when the lights are on but they are bright, like if the brakes were pressed.
They are keyed bulbs so I am going to get some regular bulbs to test with.
I have the metal buckets that ground to the body.
Ian
I had thought about the polarity issue but my understanding was that LEDs won't do anything if they are wired backwards. These do light up when the lights are on but they are bright, like if the brakes were pressed.
They are keyed bulbs so I am going to get some regular bulbs to test with.
I have the metal buckets that ground to the body.
Ian
Thread Starter
|
4th Gear
Joined: Aug 2025
Posts: 4
Likes: 0
I'm going to buy some incandescents just to test with. I am hoping that it has something to do with the polarity, but I do know that this wiring has been messed with so I am not getting my hopes up.
Thanks for the help.
5th Wheeling
Joined: Jun 2025
Posts: 43
Likes: 13
I would love for that to be the case but these LEDs work perfectly on the driver's side. I even tried swapping them over but still no luck on the passenger side.
I'm going to buy some incandescents just to test with. I am hoping that it has something to do with the polarity, but I do know that this wiring has been messed with so I am not getting my hopes up.
Thanks for the help.
I'm going to buy some incandescents just to test with. I am hoping that it has something to do with the polarity, but I do know that this wiring has been messed with so I am not getting my hopes up.
Thanks for the help.
https://www.fordification.com/tech/wiring/68-23.jpg
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