07 KW T800. All lights, blinkers, etc. on front on cab/fenders work fine. Bed lights don’t work. No marker, running, brake, or turn lights. Could this be a ground issue or could one light be bad somewhere making them all not work? I have fire past the last plug under back. Trailer lights work fine. Looking for suggestions to try. Thanks
Look for a junction box that resembles this.
JB3101.
Thanks for the reminder of why I stopped working on trucks lol.
Ok. Where would it be?
Somewhere between the dump bed wiring and the truck wiring.
I don’t remember seeing one back there, but I’ll check again. It has a six flat plug at back of truck, and it has fire past it. From there wires go to trailer plug, backup alarm, bumper lights, and rest of bed lights. In the pic you can see 3 middle red lights on but that’s all will work.
Seriously, since 2007, it’s probably been re-wired 87 times and repaired, patched, spliced, twisted, taped, soldered and 3M scotch-locked just as many times. It’s all half-rotten and corroded. Unless, 10 wheelers in your AO are different than mine. All you can do is embrace the suck and dig in. Before you know it, that old K-Dub will be lit up like a Christmas tree. If those wheels ain’t turnin’ you ain’t earnin’.
Wire tracer time. Or skip the hassle and just run new wires.
That’s right! And bought it used 2 yrs ago so got some else’s master riggin!
Is dump truck lights or trailer lights worse?
It sounds like you are facing a severe problem. It could be a grounding problem, but it could also be a problem with one morning causing the others to not work.
Have you checked all the individual lights to ensure they are all working correctly? If not, that might be an excellent place to start. You can also check the fuses and wiring to ensure everything is wired correctly. If you need to replace any bulbs, check out the store online for premium automotive lighting and auto electrics. Good luck troubleshooting!
Ground the bed
Take a jumper cable grind spots frame and bed, bed UP and on a support post, turn on lights. Then follow the bed wiring off the tail area into the truck frame. Chances are will be three wires to the two truck tail lights if fixes as usually done and more than likely been snagged torn away. Before claim Victory take a 10 or 8 ga wire, get good solder seal at bared ends of wire, crimp and heat shrink eye terminals and bolt one end to bed one to somewhere on frame. I always used a longer lead wrapped in multiple loops around a 3/8 extension so looked as a spring for flexibility.
Funny what some consider part of a service-When it comes to things as simple as a junction box it takes about 2 minutes to grab a 3/8 socket on a nut driver remove cover and spray the inside with nothing more than WD40 twice a year. When I worked Ag I never had issues doing it that way.
Is what I have on the Blue Beast, initially set up with Dielectric Grease have that in a spray as well and when comes time will spray that in there.