If everything else with the top seems to work normally except for going up, I'd check the switch and the relay, expecting the relay to be the problem.
Switch - Swap it with another, or test with a multimeter.
Relay - Pull it out and smack it a few times with the handle of a #2 Phillips screw driver, then put it back in. If that doesn't fix it (at least temporarily), someone here can figure out what points to jump to verify operation, or send you a cheap used relay - I'm sure I have one or two here somewhere.
Here's the location of the relay (Red Arrow):
