Chevrolet Biscayne Forum : “difference between wiper motor wiring on 1968 biscayne and bel-air. bel air moto...”

This motor may yet work but may require splicing or cutting some original wiring.  The aftermarket ones are like this, the GM vehicles of various years sometimes have different color or arrangement of wiring harnesses.  I would think perhaps the Bel-Air wire might be for variable speed wipers or perhaps something with the switch.

1968 Chevy's had 3 wires going to the wiper motor, a blue, yellow and a black. There was also two wires that went to the w/s washers, a yellow with black stripe and a black. If this new wiper motor contains a washer unit and the old one didn't, then use a test light or ohm meter to test the wiring for current as you move the switch from off to 'on low' and 'high'. Was the other motor one or two speed wipers? Then try pushing the washer switch 'on' and check for power. Check the wiring diagram which can be found on autozone.com  web site. Yellow is the power wire, yellow/black is switched power, black is ground, blue is speed. See attached 67 Wiring diagram

Here is a line drawing for this set up.

Hope this helps.