DODGE RAM FORUM banner

1 - 7 of 7 Posts

·
Registered
Joined
·
53 Posts
Discussion Starter · #1 ·
Has anyone verified the 7 prong trailer plug sends charge voltage to the batteries on a towed trailer that is properly equipped to accept a charge from the tow vehicle?

I have a 2015 Big Horn. Which pin in the plug carries the charge voltage so I can verify it's functioning properly?

Thanks in advance.
 

·
Registered
Joined
·
2,076 Posts
I was thinking the center, should be easy to verify by using a tester and see witch one has constant currant
 

·
Registered
Joined
·
4,712 Posts
Check the battery voltage on the trailer without it being hooked up. then hook it up and start the truck. You should see a change in the voltage. It should be what the truck is putting out to the truck battery. At least I think this would work to verify it. Could be wrong and I am sure someone will let me know if I am.
 

·
Registered
Joined
·
210 Posts
The center of a 7 pin trailer connector is for reverse lights. The + pin is #4 and ground is #1. I can't believe how many other variations are shown on the 'net though. As long as the trailer pigtail has the #1 pin wired it would provide voltage to the battery circuit.
Sometimes the center pin is called auxiliary but if you check it with a test light it will power with the reverse lights.
 
1 - 7 of 7 Posts
Top