At highway speed very slight air coming thru the vents is cold with the A/C on but otherwise no airflow so I suspect the problem is a bad blower or regulator.

To do the first basic test, I understand I need to check voltage at firewall from yellow>blk and red>blk.
WHERE?
I traced the A/C fuse wire on the strut mount and it branches off - one to the firewall behind the brake booster (no connector, just straight thru the firewall) the other goes to a 3 pin connector at the top of the wall separating the engine area from the firewall area. The wires in that connector are not black, yellow and red. they are red/green stripe, brown and another set of stripes (getting dark outside, can't tell). I tested left pin to middle and got 0. I tested middle to right pin and got 0. I don't even know if this is the correct wires to test.
With this connector unplugged with key turned on but engine not running I got loud hissing noise from the Aux air pump area (warm up air pump) .
Someone please give me a clue where to test before I rip everything open to get access to the blower.