No 12 volt power on trailer

[Fuzzy53]

Thanks all for your excellent suggestions. Rockfordroo, I checked the fuse box and owner's manual. Relay 38 is for the rear wiper. J-case fuse 32 is a 30A described as TRLR. I was not sure how to pull it to check if it had fused but does not look like it. Fuse 46 in the rear under seat box is a 20 A labled AUX PWR 1. I did pull it and it is intact. Looking at the etrailer.com link you referenced, I get the impression that someone (not me) may need to run a wire from the + terminal to the harness. The owners manual gives little detail, no diagram of harness, only says that RED circuit is Battery Feed.

[MilCop4523]

there is a relay which runs some fuses in the F150
if you have no 12v power on the trailer check the in line fuse to see if its not tripped on the trailer

[jschmidt]

It ended up being my rowing battery power relay in my truck flaking out and I have power now. The dealer is a small town dealer south of ft Wayne named knots rv center. Thanks to everyone for your input and help

[Wayne Joan]

Glad you got it figured out. Now go enjoy some camping.

[Fuzzy53]

Our 1st PUP did not have a battery so I never knew that the wiring harness was not supplying 12V for 10 years. Our 2014 Viking cws 10 PUP has a lot more electrical appliances. I realized that the fridge was not running on 12V while being towed. Recently I posted the problem on this forum. I received lots of advice and a schematic for the standard 7 blade RV jack. I learned that pin 4 was the one supposed to supply 12V to the trailer. I tested that pin with my voltmeter; no juice. Further research on the Google led me to the TrailVoy forums. There I learned that on 2003-2009 Trailblazer, Envoy and Isuzu Ascender that fuse 32, a cartridge type fuse of 30A was labeled TRLR. There is a loose red wire near the fuse box with a terminal ring which can be attached to a post on the front of the fuse box; this will supply 12V through the 30A fuse to the trailer to charge the battery and operate the fridge. So, get out your meter and check voltage from pin 4 to ground. If you TV is one of the 3 mentioned, that wire will get you power. Otherwise, call your auto dealer and ask the shop how to get 12V+ on pin4.