'07 Columbia no in cab lights/bunk power help!

Harvest time is frustrating enough without truck problems. Keeping it simple, My 07 Freightliner Columbia has all 12v outlets, dome light, bunk fan, and interior lights/sleeper in non working state of condition. Just about every piece of literature that I could find regarding fuses/diagrams panel relays has resulted in me posting this thread. Basically, ive Exhausted all the possibilities...at least to my understanding.

If anyone could shed some light for me, please consider in your reply the fact that I'm here to learn.

I keep a well maintained truck so frustratingly- theres no obvious causes. All fuses in the dash and behind driver seat are ok. Battery box clean and in line fuses are good. All other details i have are worthless and i need some mother trucking wisdom!! Thankyou!!!!

 

Down beside the seat, under the plastic cover that houses the diagnostic connector, you'll find a connector with four small wires and a large 10 gauge wire. I'm betting the connector is melted around the 10 gauge wire that supplies the sleeper with power. Chop that wire out of the connector, crimp a butt splice on it, solder and shrink tube... You won't have any more trouble.

 

I got excited because I noticed how dirt and water collects there. Prime spot for a problem. It was a little coroded but it hasmt melted and it tested okay. Still worth a shot

 

check behind the middle console on the floor under cupholders behind the middle storage case should be what looks like a small amplifier this is low voltage disconnect should have two 7/16 nuts connecting bigger gauge cables take a pair of pliers and jump those two together everything should come back if it does either replace it or if not possible to get part you can connect the two cables together with a bolt and should be back in business.

 

i have a similar problem but everything in the bunk works except for the ac blower! i already checked everything related and no luck!

 

THANK YOU..!!!
I’ve been dealing with this problem for a couple weeks, now.
While digging into the dash I saw this flashing lite. -Why is there a “warning lite” INSIDE the dash???-
After reading this post and investigating further...—BAM!— This fixed my problem. Thanks again @nasriza !

 

the lower voltage cut off ,
50 amp mega fuse below blower motor zip tied to a bunch of wires
rain shorted out fuse box behind front seat one of these or combo of them

 

ttps://www.youtube.com/watch?v=KWMu8T_R66I