The power window switches on the Pantera appear to be one of the weak points in the electrical system. The original switches on my Pantera had been replaced with German units and over the last few months the drivers side was starting to fail. No relays are used with the switches so the full load of the window motors go directly through the switch contacts. To make things worse the switch contacts are not self-cleaning. I know this because I took one apart and discovered that no wipe action is built into the contact movement. The simplest solution is just to replace the switch although the switch can be disassembled. The front cover is held on the sides by two small snap-over tabs molded into the main body of the switch. I guess it would be possible to clean and adjust the switch contacts and reassemble the switch. The switches cost about $27.00 each through Pantera parts supply companies. The switch can be pulled out of the console and replaced easily. Be sure to disconnect the battery before doing any electrical work on your car. The after market switch is shaped different than the original so you will want to purchase two new switches that match.
Mike Drew sent in this window switch information image and wiring diagram created by Bill Santos.