Hi, new guy here.

Son's got a 90 Cherokee, 4.0, 4X4 auto. Tons and tons of miles on her.

The other day he said the signals quit working. As soon as you plug in a new fuse, as soon as the blades contact, POW, it's blown. I believe it says the b/u lights are also wired through here, but I put it in reverse and the lights came on?!

Any common trouble to look for here? Been to cold to go experiment. ;)