djstorey joined us recently, and isn't able to post threads yet. I offered to help. Here's the problem, described in a PM:
Always start with checking your ground. More info would help though, type of truck, does brake light flash with turn when turned on, is it the right bulb and is it in the right way?
Does this dumptruck have a blinker assembly that looks similair to this one?: http://www.truck-lite.com/webapp/wc...10001&storeId=10001&productId=29316&langId=-1 Some may have a different looking lever, but with the same body. Most say "signal stat" on the housing. If it does, then this may be an area to look for the problem. These assemblies have contacts for light with blinker/brake using the same filiment or brake/blinker seperate filiment &/or seperate lights assemblies. They can have some odd acting problems when the many contacts aren't working correctly. If you could get a known good assembly, just unplug yours(many have a large direct multi plug underneith), plug in the good one to eliminate this as the problem. I've had them go bad with some weird light problems as a result. Good luck!! on edit: The brake lights run through this assmebly also.
Thanks for the help everyone. Yep, checked the ground. I think it might be that blinker assembly like you said Jeff. I had tried everything else and it would not work! I ended up re-wiring most everything before talking to Kenworth and I'm putting in the new assembly tonight. Hope this is it! Just bought this truck and need it to make me some money now instead of sucking it up. Thanks again!
Get one of the 12 volt testers with the sharp pointy tip - they are cheap and can be found at any auto store. Have someone push on the brake pedal and see if there is 12 volts to any of the wires to the light assembly. If not, the problem isn't with the assembly. If not, then check your left side wiring with the 12 volt tester to see which wire should carry the 12 volt brake signal. It most likely will be the same color coded wire on the right side. Start following this wire up toward the cab until you find the source of the problem. The left and right side brake wires probably join somewhere at the rear with just a single wire running up to the cab. There may be a problem at this joint.
Well, it was the blinker assembly. Just finished it and I have brake lights! I can finally get the DOT done and get working. Appreciate all the help, and Bob, I'll remember what you said for the next time I run into something like that.