Mark W

Am i missing something like a fuse. 2004.5 4 door DRW 7 pin plug will not charge my trailer batt when pluged in all 12 volt lights are dim is there a fuse i did not get or should have put in. Old truck charged through the 7 pin plug just fine 2002 Dodge.

Thanks

Mark

Casey Balvert

Your 2004 should charge as well although not very quickly due to the voltage drop in that long wire between the alternator and trailer battery. Check the fuse under the hood. 40 amps I think

handymantim

I see two possible problems:

1. The +12v pin on the 2004.5 is different than the +12v pin on your old truck
2. The battery in your trailer is TU and won't take a charge.

leadpants

I have a 2004 model and it charges my RV battery. Did you check the fuse on you RV battery?

Mark W

IT charges up fine when pluged in to 110 and the fuse on the invertor is fine. Just won't charge with the truck. Will look and see if the fuse is even there on the truck.

Thanks

Mark

PZM123

Sounds like a bad ground to me. Try a jumper from frame to frame & see if your lights are brighter.

Steve034x4

Check for power and ground at the plug. If OK, you're seeing voltage drop across 25-30 feet of 12 ga wire.
For my slide in camper, I run about 10 feet of #6 wire from the right side truck battery via a relay (ignition on) and circuit breaker to the camper battery and I can not only charge the camper battery when running, I can run the reefer via a 110v inverter. I have a couple of 80 watt solar panels to supplement, but I found that I can't rely on the 12v at the pin for much other than basic lights.

bumpytruck

Check the fuse under the hood 20A, if you hooked up without your trailer battery and it grounded out you blew the fuse!

candndelivery

get under the hood with a lite tester and check all fuses with it, I had the same problem and never could find a blown fuse by looking at them, the darn thing was blowing where you couldnt hardly see it, anyway, I cant remember what the fuse was labeled, but I do remember it was something I wasnt checking