Series : Our RV Electrical Mystery(ies)

We have a small recreational vehicle mystery on our hands. I plan to solve it, but right now I haven't.

Our truck, Mr Big, is a 1989 GMC 2500. It pulls a 29foot Puma FKSS (front kitchen super slide) travel trailer from Palomino.

The travel trailer connects its brake, running, and turn lights to Mr Big via a round 7 pin (or 7 pole) plug. Also on that plug are the brake controls so that when you apply the brakes to the GMC, the brakes on the travel trailer are engaged as well.

This is where the mystery starts.

When we plug in the travel trailer, Sheri can see the turn signals work, the brake lights work AND the running lights work.

So SOMETHING is working.

But if we plug in a 7 pin tester - brand new even - from an RV store, the tester indicates nothing is working. So that is a BIG mystery.

There is a second mystery too ! Where is the trailer harness fuse (30A) for the 1989 GMC 2500 pickup? We suspect somehow this fuse could be the first key clue on the mystery.

Anyway, we'll be figuring these mysteries out and reporting back.

Wish us luck!