I just purchased a 03 Ram with a Cummins. The driverside headlight is out along with the marker light. The taillights are out completely, no blinkers running light nothing. The "lamp out" light is on in the dash. I replaced the drivers side headlight bulb because it looked blown. I have checked all the fuses and relays. The parking lamp relay was making a weird sound. I pulled the relay out and whatever it was still made that noise. It doesnt make that noise all the time. Dash lights all work. The dummy light on the dash that says brake light is on as well. Like I said i just purchased the truck. Anyone have any ideas? Thanks in advance

 

Could be your pdc (fuse box) they are susceptible to water infiltration from the bottom which can fry traces and the front controller. I would imagine the cummins to have this same weakness in design.

 

Welcome to the site

 

Thank you I have been reading the sight for about 3 hours now. The pass side daytime running light is on no high beams. I'm going to look at the fuse box tomorrow. Does it just unplug from the bottom? The third brake light does work. I see its on a complete separate circuit though. The truck is amazing other than I can't drive it at night right now. Why does the daytime running light on the pass side only work though? the marker light comes on as well just doesnt flash with the blinker on. Dash lights work everything else does as well. I'll keep reading and see what I can find but I appreciate all of you help and input.

 

Disconnect your battery negative, then pull the fuse box, there's a bolt on the fender and a plastic screw in the front. All the connectors have locks on them, undo the lock (slide red tab down) then spread open with the white cover and work off. They are color coded.

There can be oxidization on the connectors, but the real issue is the circuit board inside. You can take apart the fuse block to further inspect it.

 

Thank you I'm going to check into it now. Wipers work sometimes as well. would that also point to the fuse box as well?

 

So I pulled the fuse box out removed the fcm. Pulled all the fuses out smacked the fcm, found a 20a fuse blown. It went to my power seat which is weird because I dont have power seats. Put it all back together and boom everything works just fine. I Don't know what I did but its fine now. I guess i'll just wait and see if it returns. It saved my about 5 grand when I purchased the truck because the dealer had it marked down because of a "electrical" problem. Thanks for all the help

 

Hopefully it will last. Good luck and welcome to the forum.

 

Glad to see it all worked out. A common issue when one side of the lights it out is the PDC so keep an eye on it