Probably the switch. Can't think of anything else it could be. One temporary fix though..... if it isn't raining, to keep the wipers from scraping accross a dry windshield, just pull both wipers off. Then only the little "stubs" they attatch to will turn.
I have two switches from my old car for sale if you decide that's what you need.
Good luck with it.
BADPONYsc I'm interested in one of those switches. Could anybody tell me if all switchs from 87-93 are the same? I purchased one off ebay and the guy said it was off a mustang but when I got it, it was like 2-3 inches longer than my stock one, and had some different connections inside the connectors. The windshield wipers won't even work, and that's the only reason why I got it.
I could be wrong but it sounds like an open circut to the switch check the wiring. Your geting constant power. Im not sure what the wiring looks like so its hard to say.
I had the same exact thing happen to me in my '94. I just pulled the fuse till i got it checked out (don't do electrical). The guy said it can happen sometimes if you disconnect and reconnect the battery fairly often for whatever reason. The wires in the switch are kind of thin and crappy and can actually melt. That's what they tell me--God knows how much of it is accurate. Just had to have the switch replaced though. Good luck.
Blk02stang - I'm sorry, I didn't even notice your car is a 96' or I wouldn't have offered the switch. I don't know if the wipers pop off like our 79-93 ones do, but it was just a temporary suggestion anyway. Good luck with it.
Also, I found out about the different switches the hard way. In my first GT (90') I had a problem where the reverse lights, turn signals, and blower didn't work. It was like that when I bought the car, so I quickly started trying to troubleshoot it. Months later it ended up being the ignition switch (go figure) and a new switch totally fixed the problem, but... One of the first things I tried was a used multi-function switch from someone on Ebay. It was listed as a 87-93 Mustang switch, so I bought it. When I got it, it was the shorter one but I figured all the connections would be the same. When I hooked it up, not only did my original three things still not work, but other things didn't either....like the wipers, etc. So I put the other one back on and continued troubleshooting.
So, actually I have a short one AND a long one to get rid of. So SilverBullit, let me know if you need this one.... the short one right? Maybe you can just re-sell the one you got on Ebay and list the proper years.
Hope this helps!