Attached is the information on the relays used to add reliability to the power windows on my '70 Cougar. The door switches often did not have good enough internal contacts to deliver enough power to the window motors. A set of relays were used to reduce the load on the window switches. The relays pull in with much less power and work well even with switches that will not adequately run the motors. The circuits are arranged to allow these to be plugged in to the existing circuits and also allow connections for using external wiring to bypass the controls (either for diagnostics or to close windows if you get caught out). It does take one set of relays for each window. The door window relay boxes can mount in the door and the rear window relay boxes below the back seat. I’ve running these for several years with no failures. BTW each relay is cheaper than a replacement door switch.
I thought I had previously posted these on this site but couldn’t find them when I looked.
PowerWindowRelay-Rev1.pdf (105 KB)