What is the common cause of a power window not functioning? Fuse, dead motor, loose wire or connector?
Where should one start first when troubleshooting a non-functioning power window? Driver's side, not that it should matter.

Both power wndows should be on the same circuit (fuse), so if the other window works, that should eliminate that potential. It could be a bad switch, loose connection or bad wire. The motor itself may not be bad, but could be dry inside and need cleaning and lubrication. A lot of variables.

It's gonna take checking the easy things things, such as the wiring beginning at the switch and making sure power is getting to the motor. In that case, the motor will likely need rebuilt, even if it needs nothing more than cleaning and lubrication.

I'm not a licensed electrician, but I play one with my own cars. I follow a simple check-off chain with all electricals: supply - switch - device. Has saved me a pile of cash over the years because 80% of electrical failures on older cars are simple problems - not hard to find and cheap to fix.

Supply = battery, fuses, fusible links, fuse block. I'm inclined to agree with Gunslinger that your windows should be on the same circuit (same fuse). Verify this at the fuse block - all circuits are marked on the block. If they are together and the other window is working, move on to the

Switch = use a simple volt/ohm meter to check for voltage coming into the switch. But, before you pull out the test meter, swap the switches. If your "good" window still works, it ain't the switch. If your "bad" window works now, replace the switch. If it doesn't, then check the "bad window" switch with a meter. With the switch grounded, you should have voltage on one side (one wire). If not, you probably have a broken wire coming to the switch from the fuse block. If you have power at the switch, activate it and check for equal power on the other wire. If there's juice on the second wire, go to

Device = motor may not be properly grounded. Use the meter to check for power coming into the motor (switch on). If no power on the wire, probably a broken wire between the switch and the motor . If there's power to the motor but the window doesn't move, unbolt the motor, GROUND IT, and activate the switch. If the motor works then some part of the window mechanicals are jammed. If the motor doesn't work, do what Gunslinger says and rebuild/replace that sucker.

Good Luck!

John

On my '68, the power wire to the relay is on an accessory circuit in the fuse block. There isn't a space marked for windows.