Breather lights

Could be something a little more serious then...I would need to see a wiring diagram to have any idea of the actual layout and wiring but I assume there could be any number of issues beyond a fuse (or maybe you put in a fuse that was bad from the factory). I assume they are wired in parallel on the same circuit, could be the relay (or relays) that control it. If you have a multimeter, trying testing the switch/relay itself that goes to it

 

I dont think this would matter but watch polarity.....
In my KW, white is ground....NOT BLACK.
Also, my KW has breakers...no fuses in the panel (1999).

Something to double check maybe? - since you didnt have any issue with blowing fuses prior to replacing LEDs ?

 

always put your meter on the fuse and check continuity. Even though it looks good it can still have an issue. When in doubt, ohm it out

 

Polarity matters on LED's, unlike incandescent. Reverse polarity=no light

 

Try looking behind the center panel of the dash. From the factory there is a fuse block there and there should be a fuse for the breather lights.

 

I too had the same problem like you runaway train. Mine was on my 06 pete 379 and I think your truck should be the same as far as the fuse panel is located. I was working on my breather lights and touched hot to ground and lost them. I searched the fuse box and could'nt find anything. What I found out was I didn't get my head far enough in to get a good look at all the fuses. Here I had missed one entire row and there the fuse was blown. My breather lights are operated by the aux switch in my cab but maybe your lights are on a different switch? The fuse panel behind the dash is just relays that i found, no fuses.

 

Mine are on a breaker along with the dash lights