Coupe Quattro Alternator interchangeability Q's

[Jonas K.]

So last night after work, 20 minutes into my commute home with 15 minutes
left, the battery warning symbol pops up in my early-90 CQ. Volt gauge
indicates 10V. Quickly shut off radio and HVAC. Voltage goes to 10.4, and I
keep a close eye as I pull over to the right lanes. 8 minutes later I get to
the Freeway offramp it's still up at 10V, and I'm encouraged that I might
actually make it home. While waiting for the light, the radiator fan comes
on, and voltage drops to 8 Volts. Uh-oh. 2 minutes later while pulling off
from a stop, the car hesitates, and I decide not to push it. Park it and
give it a good pat for getting me this far.

Battery recharged fine, and the car drove the rest of the way home after the
recharge, so all signs point at the alternator.

All wires look good, and I plan on having the alternator checked out after
work for output, but in pre-emption, what are my options?

Is the alternator on my Coupe unique to the 7A motor, or will any type 89
alternator (for AC cars) work?

Could the Voltage Regulator be the problem?

Can I repair the Alternator myself?

Suggestions on what else to check? Is the "exciter" wire a problem on these
models, as in earlier H2O vw's?

Thanks all,
Jonas
90 CQ