'13 Denali plug not charging

[NatandGregg]

My7 prong plug to trailer power cord is not charging trailer battery. I checked fuse on fuse block on truck as ok but when I checked voltage at terminal receptacle I got no voltage reading. Any ideas?

[Al and Missy]

Did you check with the engine running? Some vehicles have a relay to only power the trailer when the engine is running. You may have to add the relay. Some trucks ship with the relay in a bag in the glove box.

Al

[NatandGregg]

The truck was running when I checked voltage at terminal and when I had it plugged into Denali . When I had it hooked up interior volt meter inside trailer did not show charging (when battery had drained).

I will check with dealer as to relay.

Thanks

[Al and Missy]

Check youur manual. I looked at a 2013 2500 and there doesnt appear to be a relay but under "j-case fuses" #68 is the trailer power and it is listed as "optional".

Al

[NatandGregg]

Thanks, I did check fuse block and #68 in particular. It was there and seemed to be intact and not blown.

[danjoe91]

I was having my trailer serviced at Airstream Los Angeles recently ( where they have Airstreams -2-Go rentals). They use Denali's for the tow vehicles, and the service guy said this is a common problem with these. He said the wire that GM runs back to the trailer plug harness is too small of a gauge, and the fuse burns out all the time. Now this was on the last body style of GMC's, so GM may have fixed this problem on the new ones.

[Redleger]

Out TV pin out was different than the AS so I changed the cable between them to match

[subfan1]

On our Tahoe, I had to find a bundle of two cables near the steering column under the hood. They are taped together. One is for the brake controller and the other is for battery charge. They must be connected to the large fuse box located under the hood drivers side. One is larger than the other. You may need to buy tapered nuts to install, if I remember correctly.
BTW on our 2008 Tahoe, we have never had blown fuse issues on the charge line.

[Amsterdamer]

My '07 Yukon Denali XL had a cable that had to be unbundled and attached to the correct hot post on the fuse box. As I recall the required screw was not included so I had to find one that would work. Your '13 will be the same. I'm attaching a picture that someone else created, but looks correct.