Power window issue

[GbMichael1972]

My rear left window on my 1993 Explorer XLT Will not roll down. The motor works in both direction when I apply direct voltage. If I leave the window down, and reconnect the wiring it will roll up with no problem. I have replaced the individual switch on the door, and tested the voltage at the motor. I measure a full 12 volt when I have the switch in the up position, but in the down I only read 8.5 volts. I am wondering what might be causing the voltage drop in the down position. Any help would be appreciated.

 

[CDW6212R]

It's usually a switch, motor gearing(pucks), or a main wiring issue. Does the window work properly from the master switch?

There are two circuits for the passenger windows, two power sources. All of the wires to all motors are grounds for a given commanded circuit. So the switches simply turn off a ground to one motor wire, and apply power to that one wire.

If your window will roll up properly by the switch of that door, than the power is good to the door, that is, the secondary/passenger power is there. That should be a red/blue wire, and is controlled by the master switch, rear switch. Be sure that switch is enabled, to allow power to the other switches.

If the window will go up but not down, then it'll be that one switch of the door, or the motor assembly itself. Have you rebuilt the motor gearing yet, the three plastic pucks need to go when old.

Be careful when R&Ring some window motors, watch out for some regulator springs etc. Some are not part of the tension of the regulator, and come out easily, some you must support the window first. Regards,

 

[GbMichael1972]

The pucks in the gears were just replaced. So those are definitely not the issue. I have the same problem on the master and individual switch on the door it will roll up but not down again the voltage test is the same also 12vdc in the up position 8.5vdc in the in the Down

 

[CDW6212R]

That would be the master switch then. A voltage drop is rare, but since both switches have the same problem, all of the power goes through the master switch, so I'll say replace the master switch. All of the power for every motor goes through the master switch, the power and ground for each. Usually switch damage is in the fragile moving parts under the switch button. Pry the cover off of that switch on the master, and see how those copper parts look. It's not feasible to replace any of those components, but take a look for curiosity.

 

[Roadrunner777]

Yeah, I think Don's on it. Over the years, water can seep into the master switch assembly, more often than many because it's the door that gets used the most and it's most often the door opened in inclimate weather. The only thing I would add is an easy check, if you have not done it already, disconnect the harness at the master switch and look at the connector contacts on both sides.

If you end up buying the switch, I would not go with a junkyard part on this. The contacts sit and oxidize in the open weather, and you could end up swapping one problem for another. New is $20-$30 from various locations. I'd check those connector contacts first though, it's a 5 minute thing.

 

[CDW6212R]

That's smart too. I have bought at least three new master switches over the years, two recently. I have three trucks, so I expect to have all new switches, and they should last me as long as I own them I believe.