HELP! WIRING harness for Blazer power window tailgate
 

I am upgrading the manual roll up window to a power operated window on the tailgate on my '75 Blazer. Has anyone had experience doing this that can provide assistance on the correct wiring for this application?

The power operated '91 tailgate has two pigtails:

A. One harness has a Light blue wire and a white wire.

B. The other harness has an orange with black stripe wire and a black wire.

I am assuming one is for power to the window (but don't know which of the two), the other to a defroster maybe?

Second question, did later model Blazers include a push button switch to raise and lower the window from the drivers seat, or were they opened strictly from the key insert on the tailgate?

I am installing a Painless wiring harness, so power to the tailgate is available.

Thanks in advance for any helpful information on this subject!