trailer charging fuse

maxx1963 · 04-04-2008, 12:05 PM

i had a 2001 half ton and i put the fuse in #1 stud and trailer batteries charged. now i have a 2005 duramax and it has 2 batteries, i have been reading i dont put the fuse in the #1 stud spot with 2 batteries, is this true?

i still think i need it to charge the trailer but not sure!

pooh1949 · 04-04-2008, 01:03 PM

Can't quite remember and the operators book is kind of vague as to the number of the fuses. Under the hood on the drivers side is a fuse bos and there has to be a Maxi type fuse installed in one of the empty slots in order to charge your trailer batteries. I don't know why GM doesn't install one when the trailering package is installed at the factory but they don't. It's is aslo something that the dealers don't tell you about either unless you ask. If you have problems locating it , I'll look at mine and refresh my memory and advise.

Maury06 · 07-12-2008, 09:29 AM

I have the same problem on mine. Looking forward to your post.

Maury06 · 07-12-2008, 10:46 AM

I do have a hot terminal in my 7 pin. I do have the heavy duty towing package and according to the manual it should be there. It's the one at about 2:00 on mine, the + one on the cover.

**ob_1jr** · 07-12-2008, 01:10 PM

you still need that fuse for stud one to charge your batteries. the manual and fusebox is confusing. I had to put one on my truck to get the interior lights to work on my friend's trailer.

Maury06 · 07-12-2008, 02:19 PM

My manual says do not put a fuse in stud #1 if you have two batteries. The one terminal is hot and should charge my trailer battery.

**ob_1jr** · 07-12-2008, 04:06 PM

yeah, the manual is wrong....that is for a 2 battery gasser...not diesel....diesels came with 2 batteries.

07blkLMM · 07-12-2008, 06:53 PM

I just had my fuse put in my fuse box last week. You do need a fuse and a wire that is loomed together next to the cowl connected to your battery. When I told the service tech at the dealer that I didn't think my trailer battery was charging and I thought I needed a fuse and wiring, he said yes, thats how they all come from the factory.

ellisk02 · 07-12-2008, 07:15 PM

If it's more than just putting a fuse in, are there kits to do this, or instructions somewhere to make it easy and avoid the dealer?

07blkLMM · 07-12-2008, 07:23 PM

Quote:

Originally Posted by ellisk02

If it's more than just putting a fuse in, are there kits to do this, or instructions somewhere to make it easy and avoid the dealer?

No kits, the wires are under the brake cylinder tied up and the fuse is a 40 amp fuse. I'll have to look tomorrow under the hood to get a better idea of how to explain how they hooked it up.