Hi, have had '70 Cougar three months now and encountering my first significant issue. Rear window on passenger side is stuck in down position. Up button on master and local switches do nothing. Down button on master switch does nothing. Down button on local switch results in loud click, as if it is trying to go further down. Would appreciate your thoughts. Does it sound like a switch? I hope so (vs. motor)! If likely a switch, which one? Can I get the switches out without removing the door panel(s)?
You’re going to need to dig in a bit and do some diagnostics. The attached link has some background and some simplified wiring diagrams. I suggest starting by b\pulling the rear seat and side panel. Check for power to the motor when the window switches are pressed. That should be start with deciding on switches or motor for further checking.
https://cccforum.discoursehosting.net/t/power-window-issues-schematics-and-troubleshooting-1970-and-similar/7972/6
Thank you for suggestion and link.
Another good resource for 69-70 rear quarter window motor rebuild:
https://m.youtube.com/watch?v=cZ9BeCysP1Y
Funny as this seems……I had the exact same issue.
After a year of not working power windows in the rear.
Finally my drivers side window stopped too.
I got power going up, but not down. I talked to
Others. Researched. Long story short. I held the power button down and sprayed in CDC Electronic Spray. Over a course of
2 days I periodically sprayed all the power window buttons
and let it soak. Sure enough my drivers side window
Went 
+:point_down:t5:! The backs are slow but work as they should.
Now I dodged a bullet here. But who knows? It’s worth a try.
Thanks for suggestion. Did you just spray the outside of the switches? Without having to remove the switches or door panel or rear seat, etc.? If yes, I assume the spray seeped inside and luckily addressed the issue.?
Yes. I held the switch open (pressed down so I can spray contacts). No removing door panel, etc., every few hours I’d spray more. This went on for 2 days. Drivers side door did nothing. Now went up. And down. Now freely goes up and down! Rears were done similar fashion. Now they go up and down albeit slowly. But function as they should.
All 4 power windows work. Great for summer, with top down.
Funny passenger side door had no issues.
Worth a try!
To my pleasant surprise this actually worked. Took two tries. Wow what a great hack. Thanks so much!
Well the hack worked for one day. I guess the good news is it looks like the switch.
I fought issues with the window switches for a long time. Cleaning and/or replacing switches but kept having to tear into the door to get them working again. I finally added relays to drive the motor, this took the major load off of the door switches, they now just pull in a relay which is much more forgiving of burned or dirty switch contacts. I haven’t had a problem since. The detail for the relay circuits is in the attached link.
https://cccforum.discoursehosting.net/t/power-window-issues-schematics-and-troubleshooting-1970-and-similar/7972/7
Thanks for suggestions. I went ahead and removed the rear seat and interior panel and replaced the switch, which restored up/down function. Good for now! 