SD not charging camper batteries

[shfletchak]

Why is my 05 Superduty 6.0 not charging my camper batteries? I know its hooked up since my lights and brake controller work properly. Do I need to install a fuse somewhere on the truck? My 04 Supercrew charges the batteries, but the Superduty doesn't. I let the truck idle for about an hour last weekend to charge them and they didn't charge at all. Any ideas?
Scott

[worx]

I would check under the hood in the main box and make sure there is a fuse there for the power to the trailer, not just the lights. I don't have the shop's 07 to check which one, but the pwners manual should list it... it probibly different one than my 01 has...

[shfletchak]

The only fuses not there are the ones that say not used in the owners manual, all the fuses that are there are good. There is one fuse missing for daytime running lights and 3 relays missing for DRL #1,2 and 3. Daytime running light relays maybe?? Looked under the steering wheel too and they are all good.

[bigd4x4]

I have a similar problem. Mine does charge but Very Slowly. It must be very little current.

[jbawilliams]

As painful as this sounds, if the wire is too small (it is a #14 to maybe a #10), it cannot carry the current needed to charge a dead battery. It will maintain a battery, but not charge dead ones. It is too restrictive on flow of power. 12V does not have enough force to overcome that restriction. You can run a #6 from the battery to the trailer connector, and that will help. We camp primitive, and I have 2 batts on my trailer, and when they run low the only way to charge them is to use a battery charger. I have a small Honda generator that will run my battery charger, and it does a great job.

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Last edited by jbawilliams : 05-25-2007 at 04:15 AM.

[Evil Eye]

I've not had this problem with mine, but I have a main disconnect switch and fully charge the batt's before we head out.

[shfletchak]

OK, I looked again at my owners man and it says fuse 107 is for trailer battery charging. Aparently I miised the trailer part the first 4 or 5 times I looked. And, as you've probably guessed, its blown. Hopefully this solves the problem. I bought the truck about a month ago used, and the fuse was blown for the trailer marker lights as well, so they must have blown this one too. We camp primitive as well, with an on board Onan gen, and 2 batts as well. Hopefully this works, were off to Denali Park( Mt. McKinley ) for the weekend and a drive along the Alaska Range fishing along the way...where there is nothing... Thanks for the help...
Scott

[worx]

I just rewired our shop trailer to pull power from the plug, but mine was not putting out any power- fuse had been replaced, but seems there was no relay in place... (2001) There were 2 sets of double relay boxes- one for shift on the fly other for trailer charge and reverse lights... $10 later, I had one relay in the charge and power out the back to the trailer- hope it helps charge... no reverse lights so no relay there yet...
Did you get power at the plug?

[shfletchak]

Yes, got it working. It was a blown $5 fuse in the fusebox under the steering wheel.