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Still assembling my 71 project car and would like to test the power window motors before installing the rest of the interior. The ground straps are not mounted yet, and the battery is out of the car. Can I use the switch connectors below, put 12 volts positive into the middle socket (center wire), ground the door frame to my battery with a jumper cable, and then jump the center pin to each side socket to activate the motors up and down? Would that work? Would I damage anything in the process?
See the insulation is worn on the blue wire and will re-insulate if everything works OK.
One of those wires is 12vdc and hot all the time (power feed to the P/W circuit). One of the other wires is power IN for window UP; the other wire is power IN for windows DOWN.
The housing of the P/W motor is grounded.
You can test them that way, but you need to have that motor clamped down as it has significant torque during operation. And, you should power it with a car battery. That motor draws significant amperage (10+ amps). A BIG battery charger might work, but a home battery charger will not because of the BIG induction [power] spike when the motor starts.
Last edited by 7T1vette; Jun 24, 2020 at 07:38 PM.
The motors are mounted in the doors now, with the panels on, but not powered in the 1.5 yrs I've owned and been working on the car. That's why I will ground the door frame to my car battery, and run the positive from the battery to the power lead in each switch connector, then jump them to the up and down leads and hope for working motors, decent windows (which I've never seen), and no smell of burning wires. Thanks again for the confirmation on the test process.
The most frequent problem with the power windows is with the switches. There is significant power going thru them, and over time the contacts tend to arc/burn and build carbon deposits. This raises the resistance of the switch which reduces the current getting to the windows. Symptom: slow windows.
It wouldn't hurt for you to take a look inside those switches (mark which is which and keep parts of each together and oriented correctly so you can re-assemble them properly). If the contacts are not clean, use some brake cleaner on a Q-tip to clean them. If more is needed, some wet/dry sandpaper or fine steel wool will buff them clean. When in good shape, put some non-conducting terminal grease on the working contact sets. That will prevent air/moisture and arcing from forming again (at least, for many years) and allow you to get the most current to the motors.
Use some care and as little force as needed to bend the housing tabs straight for disassembly....and re-bend to assemble.
Testing Power Windows on 71
