slovcan

Hi guys,

I have a problem with the brake lights. The rear brake lights only work intermittently, but the hi-mount one on top of the cab always works like it should. The other lights at the back - signals, hazards, park & reverse - all work as they should all the time so its not the ground. There's a chance the brake lights may work sometimes for a 20-30 mile drive and then quit working indicating some electrical component (like a relay?) heating up. It has trailer wiring, but I've unplugged and replugged the 2 plugs under the bumper in case they were dirty/corroded - no sign of either. I tapped/banged/cycled the multi-function switch (turn signal lever) a few times and that does not get them working. Today they didn't work even the first time I checked them before I even started the truck. I took out the brake light relay after a couple of short trips to see if the parts store could match it up if necessary (they can - $18) and also to check the Aux "A" 30 amp fuse (it was good). I always check the brake lights with the park brake OFF.

So, anybody experienced anything like this - or even heard of it?

Thanks,
Glenn

Mille Racer 69

Sounds like a wire is intermitently grounding out causing the lights not to work.
I had the same problem except it was for my 3rd brake light above the back window.
a guy I know ran new wires to the fixture and it fixed the problem.

MDTAHOE

The high mount always works the replace the turn signal switch (multi function). 99.9% of the time that is the problem and that is the exact symptom.

slovcan

Thanks guys. I don't know what I dread most - the intermittent wire problem to trace or the crazy-expensive multi-function switch. Is there a way to confirm the switch is at fault before buying the replacement?

So, not likely to be the $18 relay? Everybody needs a straw to grasp onto.

MDTAHOE

Get a service manual look at the wiring diagrams, use a test light and check the ins and outs of the switch.

jlmnjem

The bulb housing inside the taillight assembly on that generation is notorious for bad connections. I've seen many of them act the way you describe, and I've repaired a few, but it's a pain in the rear and much easier to simply replace. If you remove that housing and wiggle the bulbs while someone is pushing the brake pedal, see if the bulb flickers. If so, replace the bulb housing.

Night Train

I have a 97 ck1500 and have experienced many problems with the tail lights. Because I tow a trailer a lot I always assumed it was the result of bad or intermittent wiring.

Take apart both light assemblies and check the connection between bulb and connector. You might need to jimmy the copper wire a bit on the bulb to get better connection within the inner light assembly.

I understand your frustration but this was the reason for my lighting problems. After jimmying the inner connection the problems rarely happened. Last year I bought a new set of tail lights and haven't seen the issue since.

slovcan

Thanks for all the replies. As far as the tail light CB's go, is it likely that both would fail at exactly the same time and come back to life at exactly the same time? I ask because this is exactly how it happens.

Cheers

Scott Vander Heuvel

Having problems with brake lights not working. However if I push the lever on my trailer brake they come on. any ideas?

Mont Hill

Hello I am having the exact same problem with my 98, i have not solved it yet have you