Hooked up to a trailer a couple years ago and it messed up the 4 flat side.Have a NAPA brand modulite that powers a 4 flat straight from the battery. The problem is fixed on the 4 flat side but want to wire my 7 pin into the 4 pin to ensure that it doesn't happen to the seven pin. I was wondering is there a way to just wire it all so it's powered directly from the battery? If anyone knows of a thread or has info on the subject let me know, appreciate all help greatly, thanks for reading.

 

See if this helps...

https://www.dieseltruckresource.com/...d-t242893.html