Need wiring diagram for 7-wire plug to bring 12 volts to batt from truck

[Matthew_lerch08]

have one unused wire in harness truck side , don't know which terminal to tie in to get power to battery while hooked to truck . i have done some testing . 12 v at most pins on camper side while not hooked up . on caper side . one pin seems to be ground . any suggestions ?

 

[cookie]

Re: matthew looking for diagram to bring 12 volts to batt from truck

This is what you should have on your trailer plug.

Peace
Dave

 

[cookie]

Re: matthew looking for diagram to bring 12 volts to batt from truck

This should be the truck plug.

Peace
Dave

 

[Silverado23]

Re: matthew looking for diagram to bring 12 volts to batt from truck

If the truck side +12V does not have voltage present, There could be certain conditions that affect this.

1. Test with truck running. Some vehicles must be running to have +12V present Other vehicles may be hot at all times. Test all key positions as needed

2. Fuse. Some vehicles need a fuse to be installed to activate this pin. The fuse box may have a dummy blank in the appropriate fuse holder. Replace per vehicle recommendation. The Owners manual may list the fuse but the blank will be installed from the factory.

3. Bad fuse. If a fuse is present and you are sure you tested the key positions (run/accessory/off etc) Try replacing the fuse. sometimes a fuse could be defective or blown even if it does not look bad.


Get a 7way testing plug. Make sure it tests all positions. It will have 6 lights. This will make it much easier to test the plug. An 4 and 7 way tester example
https://www.northerntool.com/shop/tools/product_200466892_200466892

 

[CoveredWagon]

Just did a quick check on my 2017 Silverado 2500hd. There are 6 fuses to the trailer connector. Checked the owners manual and they are actually in the fuse block. �� Not sure why but there is also a relay for the trailer parking lights.

 

[Silverado23]

have one unused wire in harness truck side , don't know which terminal to tie in to get power to battery while hooked to truck . i have done some testing . 12 v at most pins on camper side while not hooked up . on caper side . one pin seems to be ground . any suggestions ?

The truck wire harness may also have one extra wire that routes to the same area at the rear but does not go into the 7 way connector. It may be for the high center mount stop lamp (sometimes labeled HCMSL) and is used for a truck cap topper that has a third (center) brake light.