2008 Silverado - 12 V Wire Size For Camper Charger?

[rjulian]

On my 2008, DMAX Silverado there is a wire (red w/black stripe) that goes from Stud #1 on the fuse box to the 7 pin connector that connects to my slide-in truck camper. The wire size is #12. This wire is used to charge the battery in the camper and seems much too small. I've installed a battery isolator to protect both the truck and camper batteries from draining. But, during normal engine operation, this #12 wire is used to charge the camper battery.

Should I run a larger size wire from the fuse panel to the camper 7 pin connector, say #8 or larger?

[Spurshot]

I think you'll be fine with a #12. Your truck's battery has a similar size wire to charge it. The wire coming off the back of the alternator is about a #12 +/-. That wire should be fused in the factory fuse box. That should protect the wire. If your camper battery demand exceeds the wire capacity, the fuse will blow. I'd run it as is.

[rjulian]

I think you'll be fine with a #12. Your truck's battery has a similar size wire to charge it. The wire coming off the back of the alternator is about a #12 +/-. That wire should be fused in the factory fuse box. That should protect the wire. If your camper battery demand exceeds the wire capacity, the fuse will blow. I'd run it as is.

 

I just looked at the wire size coming off the alternator. It appears to me that it is at least a #4 or larger, it's substantially larger (2-3 times larger) than the #12 12 volt wire going from the fuse box to the 7 pin connector at the rear of the truck.

[illMATTic]

I was told by some camper guys that the #12 wire is really only good for keeping a battery backup topped off for the brakes. If you need to charge a large battery or multiple batteries from a low voltage state, a #4 or larger is needed. I wanted to set mine up to top off the boat batteries.

 

Matt