Truck not charging camper battery

Get your house battery load tested, it could have a bad cell. If ok check the fuse on the charging circuit, there should be one in the truck's fuse block.

Do you have a 3-way fridge running on DC? That can draw enough current that the stock wiring in the truck won't allow any charge into the battery.

romore:
I checked the fuse box under the hood, and the 40 amp fuse labeled "trailer" which I am assuming goes to the 7-way pin and it was good. Had the battery "load tested" at autozone today and they said it was "bad"

DWeikhert:
Fridge is on propane at the the little gas symbol is lit up. I do have 12 volt fans that kick on when it's really hot.

I am going to check if there is power at the 7 way connector. Pretty sure this battery is bad, I went to costco today to see if I could get the 6 volt batteries they have, but they are 7 1/4 inch wide and the battery compartment on my Northstar is 13.5 inches so those arn't going to work. I might look into the "universal" brand agm batteries in 12 volt they appear to only be 6.5 inches wide.

DieselBurps wrote:
romore:
I checked the fuse box under the hood, and the 40 amp fuse labeled "trailer" which I am assuming goes to the 7-way pin and it was good. Had the battery "load tested" at autozone today and they said it was "bad"

DWeikhert:
Fridge is on propane at the the little gas symbol is lit up. I do have 12 volt fans that kick on when it's really hot.

I am going to check if there is power at the 7 way connector. Pretty sure this battery is bad, I went to costco today to see if I could get the 6 volt batteries they have, but they are 7 1/4 inch wide and the battery compartment on my Northstar is 13.5 inches so those arn't going to work. I might look into the "universal" brand agm batteries in 12 volt they appear to only be 6.5 inches wide.

What am I, invisible?

Have the battery load tested by another store, just to be sure. Those guys don't always know what thery're doing and I wouldn't trust them.

Surprised nobody mentioned how useles the 7 pin 12V circuit is at the hitch. You'd be better off to run your own 4 GA charge line from the truck to the camper, especially if you're going to be investing in new batteries. Keep them topped off at all times.

EDIT: Do a search here on the forum. You'll find what you need.

Don't know if it's applicable but we found that our Chevy that was factory built for TC has a charge line for trailer battery charging but there is/was a blank fuse that had to be removed and a functional one installed for it to work. The line needed to be wired into the plug end when adding it to the installed wiring harness at the front of the bed on the frame. Since we don't use a house battery in our camper we've never connected that line to anything nor added the fuse. DH couldn't figure out why the battery on the dump trailer wasn't charging till we discovered this. Since we retired, mostly, and quit using the trailer regularly we never did the work to fix that. At least it's there if we ever decide to add a battery and all it entails. Probably not much help for you but that's our story and we're sticking to it.

No power at the 7 way plug on the upper right pin which is supposed to be the one that charges the camper. I might look into seeing what it will take to get power to that or just research how to run power from the truck battery and alternator back to the camper with some thicker wire.

Success! Ran a wire with a fused breaker from battery back to 7 pin, so we are charging now. Managed to also squeeze in two Costco 6 volt batteries into the batt compartment. Now just have to figure out how to use this Trimetric.

That's great. It does switch off when the key is off ? It needs to.