96 powerseat switch issues how to test? or fix?

Easy fix.....

I too have a 96 GT that had the same problem. If you have both switches you can dissassemble both of them by pushing apart the plastic tabs and rebuild one with the good parts. The switches have these tiny metal clips inside that often wear out. Re-lube them with silicone grease and you'll be good to go. Otherwise just install a manual seat track (like I did) and be done with it. Be warned, if that seat switch isn"t fixed it may drain your battery and/or burn up your seat wiring (which also happened to me). The seat track from the passenger's side from a 94-98 will fit and so will one from a fox-body stang, but you may need to drill a couple holes in the seat track for the fox-bodies.

While this is 13 years later than the original poster, my '96 Mustang Cobra power seat switch stopped working in 1 of the directions. Disassembled the switch and everything looked fine. Cleaned. Same problem. Volt meter read inconsistently. Hmm, after looking at prices and availability for parts in 2023 online and local junkyards, I was measuring to model a 3D replacement built from two DPDT switches (because that's all the joystick/switch is).,,,and I happened to tip the part over and gravity pulled out of the corner contact pins out. It likely was manufactured with a subtle defect. So, if your switch is mysterious broken, carefully examine the pins. For the solve, I used some flux and solder to bond the pin to the right area and then the volt meter read consistently. Good for another 27 years.

FYI, if your seat is stuck in one direction making it difficult to access the bolts for removal, and the joystick won't move it in the opposite direction, and you have access to the harness, you can reverse the polarity on the seat "input" connector and use the "good" direction to move the seat for access.