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1990 Camry I4 DX FWD
132 Posts
Discussion Starter · #1 · (Edited)
I came across this thread on an auto-up driver's window by Charlie and wanted to give it a try on my 1990 Camry:

It looks like Toyota designed these cars to have both an auto-down and up driver's window and but disabled the "up" function in production. I'm guessing this was a decision made to avoid lawsuits from people getting their head or arm stuck?

As it is, if you enable the auto-up, the window should stop after a second or two when it hits an obstacle like your head, but won't back down like it might in a 'smarter' implementation. So, be warned, this is potentially dangerous.

Take out the driver's side window control unit. It's on with one snap in the front, then pull forward and up. Disconnect the wiring harness and remove.

Take off the rear cover to get to the circuit board. Do you see the 2 empty holes in the lower right of the board? The diode anode (+) goes on the bottom, the cathode (-) goes on the top (towards the center of the board).

What we're trying to do here is add a diode between the up switch and the "hold" circuitry which keeps the motor engaged. It seems to measure the current used by the motor, and disconnects it when it exceeds a threshold (when the window reaches the top and runs into the frame).

I used a IN4005 rectifier diode for this. Make sure your diode is rated for at least 16V reverse. I don't know what the current requirements are, but I'd imagine 1A+ is sufficient. You may want to measure the current draw to make sure. Choosing a diode with a too-low current rating could cause it to break or catch on fire.

I recommend adding the diode by threading it into the gap between the PCB and the top of the unit and down into the existing holes. You can take everything apart to get to the front but there is a mess of loose contacts, springs, and a retention spring for the window lock switch in there that are a PAIN to get back together.

Thread the leads through.

Solder to adjacent exposed pins.

Now, there's a mechanical switch position for auto-up. You need to shave off some material from the back of the driver's window switch to allow it to go into the auto-up position. I forget how the internal switch works, but once you do this, there will be a definite "click" when you pull it all the way up, just like for auto-down.

Remove the horseshoe clip, pull the axle rod out, and shave the plastic down to match the passenger's side switch.

Put everything back together and make sure you feel a click when you get to the auto-up position.

It works! Really well too, no oddities that I can see (so far). :cool:

- Craig

3s-gte in a Camry?!?
'89 Camry Alltrac
9,089 Posts
Maybe the lack of write-up is why people don't do it more often around here. Thank you for doing the real work to get the info out there!

The auto-up function is enabled on the JDM (and possibly rest-of-world) cars - its just a lawsuit problem in the US. Now, if we could just get auto up/down on the passenger window... :D

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