Blowing tail light breaker

[RyanC]

2007 freightliner century cat c15
Complaint: tail light breaker getting hot and shutting off. Said it only happens after about 45 minutes to an hour with trailer hooked up. Has new headlight switch, new breaker, and a bunch of other random wiring and connectors people replaced on a wimb. And the truck to trailer wiring all has been replaced. Truck hauls a different trailer every day and its same with all.

So I got it today after a 30 minute bomb tail with all lights and accessories turned on. The breaker wasn't hot, so I pulled it and put a wire in place and took an amp reading, 3.8 amps on a 15 amp breaker. Reinstalled breaker and shook everything around hooked it up to a trailer with all led lights and it only went up to 4.4 amps. While I was poking around the b+ terminal on the fuse box burned me a little. So I shut everything off pulled the b+ feed wire and nothing looked bad, cleaned it and reinstalled it checked all voltages on posts and at all fuses all reading 13.8 to 14v so I checked amperage on b+ terminal and it was around 20. Let it run for a while and nothing got hot can't find any problems.....

Anyone have any experience or issues with any of these things? Nothing in anything I looked at gives me a direction to chase for shorts or anything.

[Rawze]

using a thermal camera usually reveals where the problem wires/fuses are ...

[RyanC]

Any recommendations for one to use with android?

[Rawze]

(12-28-2018 )RyanC Wrote:  Any recommendations for one to use with android?

flir makes a crappy one for android for bout $300 or so. Better then nothing.

The one i have is a thermapp. Cost about $1000 or so. much better quality.

[Waterloo]

We had a similar situation on a Pete, it was discovered the ground strap from the fifth wheel to the frame was broken. Just thought I would throw that out there... The strap on the Pete was a flat braided stainless steel wire, a weave so to say, around a foot long. Repaired that and issues went away. We were a drop and hook operation too.

[RyanC]

Might just bight the bullet and order that thermo cam.
Check the ground strap as well.
On vacation and trying to help father in law out with some problems he's having while I'm down here. He's getting raked over the coals on a lot of this stupid stuff that no ones actually looking at just chucking parts and pissing in the wind.
Got a lot of other stuff knocked out atleast.... saved him couple thousand. Would be nice to get this last one for him.
Thanks for the help guys.