Blower Motor / Regulator (Again...)

[wally]

A few weeks ago my blower motor got intermittent, slamming the car door as suggested here fixed the problem. After checking controlling voltage from console, strip fuse, etc, I assumed my brushes were gone, following a tip here I got a brush kit from **************. The brushes were indeed gone, and replacement got the blower going again. I was feeling pretty good that I saved all that money on a new motor by only replacing the brushes, but not for long.

A week later the blower quit working completely! Slamming door had no effect. Back through the usual checks, (strip fuse and controlling voltage still good). Took wiper, moulding, etc out to access motor. Hot (red) wire to motor showing 12V with key on, as it should. Jumped motor to ground and it fired right up. So my soldering job on the brushes held up, at least! I don't have a heavy-duty ammeter so i can't test current draw on the motor.

Now it is looking like the regulator blew. The voltage between the blue & red for the motor is at a constant 4V with key on and changing fan speed on console.

Is the blower motor at fault here? Is there any reasonable expectation that replacing the regulator will not cause this to happen again in short order? As you know the regulator runs about $280. I'd rather replace both blower and regulator if there is a chance this will happen again, even if it will cost me over $600.

The blower seems to spin freely, about 1 1/2 revolutions before coming to a stop, should it be more free than that? The bushings are still tight from what I can tell, no freeplay at all.

I've heard that (apparently) the blower motor draws more current with age. This makes no sense, assuming the bushings and brushes are good. Based on what I understand about the regulator (it dissipates more heat at lower fan speeds / current draw), it doesn't make sense why a motor that draws too much would blow the regulator.

Also the strip fuse is still good, how likely is it that the regulator blows before the strip fuse?