Truck power to trailer
One of the pins on the 7 pin connector is supposed to supply power to the trailer. Mine doesn’t seem to be working. If I measure the voltage at the battery, it does not go up at all when I connect t...
Forum Discussion
BFL13 wrote:
What is the trailer battery voltage with the 7-pin disconnected? Do the lights and fans work with the trailer battery connected, but the 7-pin disconnected?
Need to find out if the 7-pin pos is before or after the DC circuit breaker by the battery pos post before blaming that breaker (or it might be a fuse) since the battery voltage did not rise.
(You said the lights don't work with the battery disconnected, which is to be expected.)
Check the voltage at the 7-pin of the trailer cord (that goes in the truck's) That should be the same as the trailer battery's voltage. If none, find the wires from the trailers 7-pin cord that go onto the battery and see if they are connected to the battery. The ground wire of that cord might not be grounded to the trailer's frame. The positive (pin #4 wire) might join in with another pos wire, and then that wire has a fuse before going onto the battery pos post.
With the 7 pin disconnected, and battery connected, everything works fine. Battery voltage is 12.7, and voltage at the 7 pin is the same. If there is a blown fuse, why is there voltage at the 7 pin?
It seems like there should be a fuse between the 7 pin and the battery, but if so it is well hid.
With the trailer battery disconnected at the battery, and the 7 pin plugged in with the truck running, , shouldn’t the truck power the lights?
I’ve been trying to avoid pulling the power panel out to look for more fuses and connections behind it, but I may have to do that.
