I keep blowing my 20 amp fuse on the truck for trailer running light every time i hook up RV trailer running lights. I have never had a problem with my bass boat or pontoon with some leaky lights. Hook up my 32 ft Cardnial 5th wheel by forest river, and it blows the fuse with in 10 miles. I bought one of those adpater that tie in to the factory plug factory connection and ran it to the bed. It looks high quality and sealed correctly. Could the few more light be enough to draw over 20 amps? I was thinking trying a 25 as I wouldn't think that would cause a fire. I have checked for shorts and ground and found non visually or with the VOM. Any one got any idea. I can't trace the wires once they go into the trailer.

Thanks.

 

You have a short and need to find and fix it.

 

Yea, you're going to have to start pulling bulbs/connectors and checking 1 by 1.

I've also had a 7 pin connector short out on me as well, start with the easy stuff first...

 

Check your owners manual to verify that 20 amp fuse is the correct size. My truck uses a 40 amp fuse for the trailer/tow circuit.

 

You don't mention what model the 5er is but some of those things were notorious for corroding the lamp receptacle and shorting out. I'd start by checking those. I've also had the factory 7-way plug short out. I bought a better one and changed it out.

 

The manual on the truck doesn't say anything So i will see if can find the manaul for the camper. It is a 32 LX. I don't doubt there could be a short but it would have to be to ground in order to blow the fuse and the VOM doesn't show it at the connector plug. I will double check the new plug I bought as well. THanks for all the input. More do to keep me occupied in between pulls at Schieds this weekend.

 

some of the circuits like signal lights, brake lights, and tail lights go through the pcm and if it trips hard enough you have to back to the dealer and flash to reset. about three times then new pcm. i would change most of the bulbs out to led.s get a amp meter and check current draw. after you get it fixed build a box consisting of a six circuit fuse panel and four relays get a 40 to 60 amp thermal breaker and connect to battery run 8 gauge back to the box mount the box in the bed driver side near tailgate this will relieve all load from pcm

 

I thought the 03 didn't have that PCM connections just the new trucks? Would not resetting it cause it to keep blowing? I tested all lights I could get the covers off since the rain screwed friday up at the pull. Nothing to ground and no shorted connectors. Will have to do some more checking now that I have more tools available.