1969 Mark AC Issues

Hi,
I have had Lincoln Land service my Mark before, and I even donated a ’70 parts Mark to Chris.
While driving at about 60 MPH on 75 , I heard a snap and simultaneously noticed a drop & then rise in the alternator gauge.
I turned the ATC off, and stopped & checked for a bad belt, but all was in order.
After I got home from a 70 mile outing, I cut the engine off and placed the ignition in the run position and also in the accessory position.
In both cases, when I placed the ATC on, the noisy blower seemed to try to start, but the alternator gauge immediately dropped to the far low end.
What went wrong, and is it easy enough to service myself ?
Denise was always my chief contact there and I miss her helping me, so I am going to have to go about it the slow way.
Are you able to help me figure this out ?
It’s a long trip to Clearwater from Fort Myers.
Thank you in advance,
Charlie
—————————————————————————————————————-
Greetings Charlie –
We here at Lincoln Land were deeply saddened by the loss of our Denise. She had a special personality that made her customers feel at home. She will always be remembered here at Lincoln Land.
The “snap noise” that you describe is unusual and I cannot imagine from your explanation what it was, but the fact that you have a severe electrical draw along with a noise in the blower motor area indicates a problem in the blower motor itself. If this excess draw continues from the blower motor ( even if it operates ) wiring damage soon can occur. The blower motor electrical draw can be tested to verify this but the blower motor noise that you report leads me to believe that it is your problem in this case. Another possible draw could also be the compressor clutch. If you unplug the compressor coil at the compressor and operate the system with the compressor unplugged you can verify this. I do suspect that If the blower noise is internal, the blower motor itself will need to be replaced. The blower motor is removed through the right kickpad recirc air door cavity under the dash. This job can be a challenge to any one that is not familiar. Corrosion in the area is also a possibility. Be prepared with a new or good used blower motor available before removing the old one.
A service manual is a great asset for some of these tests and procedures. If you need more information, we can send you a copy of this section from our shop manual.
Sincerely,
Bill