So on my 99 1500 5 speed I don’t have any reverse lights. New bulbs, good fuse, clean bulb connection. Where should I look next? I’ve searched the entire harness for a bad ground etc.

 

i would recommend checking out the backup light switch on the transmission. connecting the 2 wires at the transmission should make the lights come on if everything is working as it should. if not measure to see if there is power at the switch. also make sure you are checking these things with the key in the run position since it likely doesn't get power with the key in the off position.

 

I second that. I find it crazy that a few years ago when I was working on my 91 K1500 replacing the distributor module I had to go to the parts store 3 times to get one that actually functioned. Wild that NEW parts are defective. QC doesn’t exist anymore.

 

Be sure to check out the wiring inside the steering column. I just had a similar issue with my wife's truck. Turns out something is loose in the steering column when you wiggle the gear shift a little the lights come on, then you barely touch it, or let the truck move and they go out. I haven't had the chance to deep dive the issue yet, but it's definitely in the steering column.

 

mine is a manual

 

Ah, damn, ok. nevermind then lol