1) Yes, it is a 12 volt truck.
2) The hot wire from the ignition switch goes into a small fuse block that also powers my turn indicators. Those are working fine. That tells me there is no insulation break from the ignition to the fuse block.
3) The motor was installed when I purchased the vehicle. The wires all appear news. The wires are red, white, blue and yellow. Yes, the ground is likely from the bolting to the body.
4) The switch has two speeds.
5) Saturday I disconnected the turn indicators, put in a fresh fuse for the wipers, turned them on and they moved for two cycles, and then the fuse blew again. I replaced the fuse and it blew immediately without cycling at all.
6) There is never any smoke.
7) I'll try a new inline fuse to see if the block is the issue.
8) I'll check to see if the wire is wrapped around something that could be causing a break.
Thank you all for your insights.
