2nd Gen Non-Engine/Transmission Brake Lights flash while at rest--ign off...

[JesseGray]

Because of an electrical problem with the brake lights, I have to disconnect the battery ground wires.



When the ground wires are re connected, the brake lights come on steady or the will flash. I have checked the brake controller and it is working correctly. All other lights and accessories are working correctly. The Stop Light switch on the brake pedal is not sticking. Almost forgot, there sounds like circuit breaker clicking--the sound comming from behind the A/C Heater controls or center of dash.



With the trailer attached and batteries disconnected the truck is either getting 12 V or a ground from the trailer.



Without the trailer, disconnecting the driver side ground first, the under hood light goes dim but not out. disconnecting the passenger side battery first, there is no change in the under hood lights brightness.



Anyone else have this situation or know where to start for correcting the problem???

 

[JCyrbok]

Because of an electrical problem with the brake lights, I have to disconnect the battery ground wires.



When the ground wires are re connected, the brake lights come on steady or the will flash. I have checked the brake controller and it is working correctly. All other lights and accessories are working correctly. The Stop Light switch on the brake pedal is not sticking. Almost forgot, there sounds like circuit breaker clicking--the sound comming from behind the A/C Heater controls or center of dash.



With the trailer attached and batteries disconnected the truck is either getting 12 V or a ground from the trailer.



Without the trailer, disconnecting the driver side ground first, the under hood light goes dim but not out. disconnecting the passenger side battery first, there is no change in the under hood lights brightness.



Anyone else have this situation or know where to start for correcting the problem???

never had that problem so I am just spit balling but with the clicking noise have you checked the hazard switch and/or flasher module?



J-

 

[JMDancoe]

My first suspicion would be you have a wiring problem in the trailer or "non-matching" condition in the truck to trailer wiring connecter. This is due to your third paragraph "trailer attached and batteries disconnected". You obviously have a feedback from the trailer. Either a backfeed through the ground system or a non-matching wire connection at the trailer connecter. I hate to say it, but this may have now burned a circuit in the truck and will be tough to trace out. Check the 12v system on the trailer and see if you can find something out of sync there first. Anything "hot" going from the trailer batteries to the truck/trailer connecter? If so, does it match correctly with wiring on truck side of connecter? As far as I know, you should only find one wire "hot". The wire that allows the truck to charge the batteries on the trailer.

As for the "clicking" in the dash, that is why I suspect a burnt circuit in the truck now. You will probably have to go into the dash and "feel" for the clicking unless you have a stethascope with a long probe. Find what is clicking and replace it. If you are lucky, it is a circuit inside of it that got burnt. Be sure all grounds are clean and tight. One of the most common electrical problems is poor grounds. Let us know what you find, as it may help someone else in the future.