Power Windows Supra/Soarer/Celica/Cressida - UPDATE!

[Mos]

For future reference, the Power circuit breaker (14) supplies the power to the central locking (directly) and power windows through the Power Main Relay (D).

On the Power Window Master Switch diagram you can clearly see pins 1 and 5 are common between the two switches - therefore one of them is power, the other is ground. Ground will be white/black, the other will be power. If I had to guess, I'd guess the power would be blue/black but it could be one of the other two wires.

Before it stops - does the window slow down? or does it just stop? Does it sounds like it's going at the right speed? Could it be rails/mechanism caked up with crap causing the motor to draw too much current and heat up like a barstool?
I had a power window setup out of a burnt out car that worked fine after cleaning up all the burnt grease - so I'm curious what would make your motor fail....

Mos.

[Admiral coFF33]

Hi Mos !

Yeah , the window is chugging and going quite slow, and even slower jus before it has a spak out and stops.

Give it a few seconds and try again , and it continues to go up for a little bit, then stops again.

I cleaned and lubed the rails with WD40 and INOX as i had the same idea, that they might be filthy and gripping on the wheels that ride along the rails .. but its still performing the same.

I still cant figure out why the solenoid is overheating, as the drivers side window gets no where NEAR as hot as the passenger side.

I guess there must be something making the motor have to work harder , and caked up shit is all i can think of ...

Id take the motor out , but as far as i can tell i have to take a lot more apart off the door than i'd like to .. as the window glass cannot simply be disconnected from the rails.

[thechuckster]

before you needlessly destroy a motor by pulling it apart, have a close look at the switches (or relays if used) that control the windows. You'll find that the contact surfaces will be heavily pitted and barely touching.

The cause of the slow motor is more likely to be the poor thing trying to run on 6V rather than 12V due to voltage drop across the badly pitted/carbonised contacts.

You can pull the door switches apart without breaking the bits that hold the switches together.

If you want to test this assumption, put the multimeter across one of the terminals of a motor and the chassis, set the multimeter to read 0-20V DC, get a friend to operate the window switches. If you get way under 12V, have a lookaht e switches as noted above.

[Mos]

Electric motors are somewhat self regulating. They produce a back EMF (electromotive force - Voltage) that "regulates" their current consumption. This back emf is proportional to speed - if the motor slows down the back emf reduces and the motor pulls more current to try to restore the equilibrium. This extra current is what's causing the motor to heat up.

The voltage will drop because the harness is not designed to run the higher currents continuously and voltage drops across the harness will occur - it's not a sure sign of bad contacts. If the contacts were faulty the motor wouldn't be getting hot - the contacts would get hot and would eventually burn or cause melted plastic.

You should be able to disconnect the power window assembly from the window so you don't have to pull the window out. You can then get an idea if it's the scissor assembly (if these models use these) or the motor, or the window channels/runner, or the switches.

Mos.

[Dale]

It worked fine when you applied 12v straight to that motor though didn't it?

[thechuckster]

fwiw: my ma61 windows went at half speed and very slowly with engine off. I removed the switches in drivers door - I discovered that the contacts were barely touching and had significant damage from arcing - I cleaned them and reset the leaf springs holding contacts together/apart so they made soid contact ... window speed issue went away.

[MotivatedSeller]

Make sure you haven't got window lock on

If there's no power going to it then you'll just have to follow the wiring to the power source. There's probably a fuse somewhere in some hidden location that's gone, and is probably a bitch to get to, and is some weird Jap fuse that you can't get in Aus.

You tested the motor by connecting a power source to it? e.g. 12V power adaptor from tandy/dse/jaycar?

If you can't find a decent solution to it.. then why don't you just rig up a new switch... run 12V from the battery to the switch and hey presto, your mum's your uncle and your window works...?