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Old 09-20-2019, 01:18 PM   #1
elorenzof
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3RD brake light issue

Hi all, happy Friday.

I purchased an LED 3rd brake light from Robznob11 and installed it. WORKS GREAT WHEN STOPPING! only if the driver or passenger door is open. ??? wired it into the brake light switch white wire. 1970 c10 2wd. any suggestions?
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Old 09-20-2019, 01:23 PM   #2
71gmcC15
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Re: 3RD brake light issue

Is it grounded though the door swiches? That's my only gess
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Old 09-20-2019, 01:55 PM   #3
elorenzof
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Re: 3RD brake light issue

Quote:
Originally Posted by 71gmcC15 View Post
Is it grounded though the door swiches? That's my only gess
thank you for your response i gotta check my grounding just like you guys said.
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Old 09-20-2019, 02:41 PM   #4
mgkgmc
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Re: 3RD brake light issue

You could just drive with the doors open just a thought.
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Old 09-20-2019, 03:41 PM   #5
elorenzof
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Smile Re: 3RD brake light issue

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Originally Posted by mgkgmc View Post
You could just drive with the doors open just a thought.
TEChNICALLY id just have to open the door when i stop
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Old 09-20-2019, 09:13 PM   #6
BigBird05
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Re: 3RD brake light issue

Did you replace the brake pedal switch to a 3 wire? You need a dedicated circuit going to the 3rd brake light.
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Old 09-20-2019, 09:43 PM   #7
toolboxchev
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Re: 3RD brake light issue

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Originally Posted by mgkgmc View Post
You could just drive with the doors open just a thought.
Naw, its made that way from the factory so when you go to stop the bird has to fly also!
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Old 09-20-2019, 01:24 PM   #8
demian5
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Re: 3RD brake light issue

If I read this right, for some reason its using the same ground as the courtesy lights. If so, when the doors are closed, there is no ground for the light - that is why. You have to ground the light separate from the courtesy light circuit.
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Old 09-20-2019, 01:55 PM   #9
elorenzof
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Re: 3RD brake light issue

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Originally Posted by demian5 View Post
If I read this right, for some reason its using the same ground as the courtesy lights. If so, when the doors are closed, there is no ground for the light - that is why. You have to ground the light separate from the courtesy light circuit.
THANK YOU. I'll pull off the cargo / 3rd light and see where it is grounded and that sounds like you nailed it perfectly.
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