Help with power windows 1963 Galaxie

Calling all 1963 wiring experts,
Here's a challenge for you. I'm at my wits end with these nonfunctional power windows. These are the original windows and motors on our 1963 Galaxie 2-door sedan. They worked in 1986 when the car was resuscitated, and they worked through the 1990s. But since about 1999, when the car was stored in a somewhat damp garage, they don't work today. None of 'em! This strongly suggests a systemic fault has taken out all the windows. Any help you can offer is appreciated.

Here's the situation as it stands.
1) First off, there is no fuse on these windows.
2) The 30 amp circuit breaker attached to the starter relay next to the battery is GOOD.
3)I got some funny voltage readings off the power window relay mounted on the firewall, so we replaced the PW relay with a new one from Greg Donahue.
4) With the ignition key in "ACC" or "ON" I get power to the master switch in the driver's door. I get power to the switch on the master switch going to the driver's door window motor. And, I get power all the way to the coupling that goes into the motor, in both directions (that is, up and down, which are red and yellow wires respectively).
5) I pulled the driver's door motor and hooked it up on the bench to a 12V batter charger. It works! The shaft spins. However, this is intermittent. I'm unsure (moron) if the motor or my bench test skills are faulty.

The power going to the motor strongly suggests the problem lies in the driver's door motor. BUT, none of the windows work. So are all the motors bad? Possible, but unlikely. Plus, the driver's motor works (sometimes) on the bench. I may send the motor off for a check-up to a 1958-66 Thunderbird parts purveyor, who sells and repairs motors like these. (I'll post this also in the Tbird section, and the general tech board.)

Am I missing something? Is there some secret circuit breaker somewhere? What dumb thing am I forgetting? There is a circuit breaker under the dash just under the fuse box, which has a yellow-black and an orange-white wire going into it. According to my several wiring diagrams, the yellow-black wire is from the wiper switch, and the other wire should be black, not orange-white. I have suspected this circuit breaker does more than run the wipers, but shorting it out did not help the windows. I could add that, along with two-speed wipers, for powered options the car also has a dealer-installed spotlight mirror in the driver's door.

Many thanks in advance to the FM community. Sorry for the long post, but I wanted to include any relevant details. My car electrical skills are meager, at best, and I greatly appreciate the help. Let me know if any photos can help.

Jay

Firstly, I think you should go buy a tube or can of Di-electric grease and take all the control switches apart and clean them and lube them with the grease. This will ensure that your motor's get the voltage they need.

Then freely lubricate all your connections with it. It's thick and good!

Maybe remove each motor again then bench test them BOTH directions, re-install them, if they struggle to lift or dont lift at all they likely need rebuilt...

How much are you going to pay this T-bird guy to fix your motor(s)? The guy I talked to wanted $150 for each motor. I went with Nu-relics for a brand new motor retrofit on my regulator for $200.

64 Mercury,
The vendor is BirdNest. They sell reconditioned motors for 125, plus a core fee of 75. The guy thought he could probably rebuild mine ("we do it every day") for less than 100. I've thought of Nu-Relics and other windows, but I really want to retain the original regulators and, if possible, the motors. Here's the link, click on the online catalog and search for "power window motor", your choice of year. 1963 Thunderbirds and Galaxies seem to use the same motor, with three wires.

Bird Nest 1958-66 Ford Thunderbird Parts

Sensei Going Broke,
Thanks for the advice. I will get some di-electric grease, can't hurt, and I've got plenty of the other (elbow) grease on hand. This window deal is one of those things you can't really take to a mechanic, not without a big budget. It might take them a day and a half to get it working, and at $60/hour that adds up quick. So I'll keep plugging away.

The fact that I get 12V all the way to the motor--and in both directions on the switch--suggests that current flow is not the issue. But the grease might help more than the contact cleaner I've been using.
By the way, I'm going to start on the trunk lip rust soon. I'll keep you posted.

Jay

Taking it to a mechanic like myself you would pay a flat rate for the job.
But 90% of "Regular" mechanics cannot perform that kind of repair because they are retarded....

With Nu-relics you keep the stock regulator but they modify it to accept a new style motor.

Check the grounds . You have power to the motors make sure they are grounded