I have a 68. Had some electrical work done in the dash. When the fan (heater/ac) motor was hooked up, it made a constant, high pitched eletrical whining sound -even with the fan turned off.

When I asked about that constant sound, the electrical guy said; That's common in the older cars. It comes from the blower motor.

What's up with that? I don't remember my 70 having that sound. Is it just a matter of replacing the fan motor? Anybody heard this sound before? Thanks!

The blower motor is never completely off. Even in the lowest setting, it spins slowly to provide some circulation.
It is possible that the elec blower motor is going bad, or, maybe the squirrel cage fan is rubbing on the case. Regardless of what is causing the noise, you are MOST PROBABLY going to need to pull the blower. IT'S LOTS OF FUN!!!!!!!!!!!!!!!! :(
It requires PARTIAL removal of the right inner fender. It's BEST to completely remove the right inner fender, but it CAN be done by removing several bolts that attach the inner fender to the outer fender and firewall, then twisting and pulling down the rear portion of the inner fender to gain access to the blower motor. Where the inner and outer fenders are attached to each other at the wheel opening MAY be a challenge. The bolts screw into J-nuts, and sometimes they are so rusted that they have become seized. Because of their location, it is difficult to shoot penetrating oil, WD40, etc onto the threads, but do your best. If a bolt has become seized, and when you're turning it, the weldnut may break loose from the J-clip. They you have to get a die grinder and cutoff wheel and cut off the bold head, get a new J-nut and bolt to put it back together. LOTS OF FUN!
But, be patient, take your time, shoot plenty of penetrant up into the bolt area.

Now, for some personal input on this design. I SERIOUSLY (NOT just spouting words) would like to physically get my hands on the human being that designed the location of the blower motor on these cars!!!!!! I think it would be worth the charges and fine for assult and battery! That blower location has to be about one of the dumbest designs ever done to a car. In 73, someone got smart and positioned it on TOP of the plenum box.

Ahhh, great. So you figure a blower motor replacement should do it, huh? I was planning on that anyhow because we're starting an AC delete effort to clean up the engine bay. Just bought the car.

I figured that at this time, I would just replace the heater core and blower motor while I have the chance. Also have a near-new, chromed AC compressor and chromed bracket. Anybody interested? Posting on ebay this weekend.