I ran through some water holes a couple of weeks ago, and a few days later lost my park lights. I found that if I disconnect the two plugs behind the driver front wheel for the rear end, the fronts would work. I cleaned the connector, and plugged it back and the fuse blew again. I have been fiddling with it for a few hours now, and no luck. The weird thing is that I show 12.5 volts to BOTH of the contacts for the park lights in the fuse box. When I throw the park switch, though, it drops to around 1.5 volts on one leg. Odd, huh? I started checking other fuses, and I have 1.3 volts on one leg of the maxi-fuse for the trailer lights. Can some one recommend something? I need to get her inspected in a few weeks....

 

Sounds like you have a trailer harness.... they sucked from the factory. The connections would get cruddy, and decay, and give all sorts of trouble. I would look where the trailer harness meets the rear harness first.

 

and check your grounds on your frame towards the bed end

 

When a circuit is energized, and you test from either wire, you will read voltage on the completed circuit. But as it is blowing fuses, it is shorted eitehr from junk or damaged wire....