1978 Jeep CJ5 Brake light

Tiny
JON447676
  • MEMBER
  • 1978 JEEP CJ5
  • 6 CYL
  • 4WD
  • MANUAL
  • 102,000 MILES
The left brake light is not working even though there is voltage. The directional light works and I eliminated a ground problem by connecting the housing directly to the frame. There is a trailer wiring harness installed and both the yellow (right) and green (left) wire register the same voltage but only the right works. I'm stumped!
Friday, June 26th, 2009 AT 9:16 AM

7 Replies

Tiny
RACEFAN966
  • MECHANIC
  • 5,029 POSTS
Ok so tell me is it the light on the Jeep not working or is it when you hook up a trailer the trailer light is not working?
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Friday, June 26th, 2009 AT 10:05 AM
Tiny
JON447676
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  • 4 POSTS
Both.
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Friday, June 26th, 2009 AT 4:50 PM
Tiny
RACEFAN966
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Ok have you checked the ground to that light socket on the Jeep? If not check the ground and make sure it is good and clean.
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Saturday, June 27th, 2009 AT 9:09 AM
Tiny
JON447676
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  • 4 POSTS
I have checked the ground, added a separate one to verify, and the other lights in the housing are working fine. Only the brake light is not working on the jeep and trailer, even though there is voltage.
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Saturday, June 27th, 2009 AT 10:52 AM
Tiny
RACEFAN966
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Have you checked the bulb to make sure it is good? If not then check it or if you haven't yet replace it as they are cheap or swap it with the other bulb from the other side. Let me know how it goes.
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Wednesday, July 1st, 2009 AT 9:16 AM
Tiny
JON447676
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  • 4 POSTS
Yes the bulb was checked and the light housings were also switched to confirm. A test light works on the tail light and trailer wiring harness but still no brake light.
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Wednesday, July 1st, 2009 AT 11:44 AM
Tiny
RACEFAN966
  • MECHANIC
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Ok remove the bulb and get a volt meter and probe the term and then check for voltage. If you notice there are two terminals inside the socket one is for park lights and the other is brake and turn check both terminals for power and let me know how many volts are at each termilnal ok. Thanks.
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Thursday, July 2nd, 2009 AT 9:17 AM

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