The driver's window on my LS430 is intermittent. It tends to go down, (in auto or non-auto), but when I try to close the window it goes up a little then quits. I wait a while and it will go up a little more each time I try it until after several attempts it finally closes completely. I've looked through the forum and people are saying it is a bad MPX module. They say to take one out of another door and try it to see if it is the MPX controller. The MPX in the driver's door has 4 plugs and all the rest have 3 plugs. Can I still try a MPX module out of the Left Hand Rear door and just hook up the three plugs just to try it out? This car also sat a very long time and killed the battery. I had to replace the battery. Must I reset the window controller or anything like that?
Otherwise, is there a way to test the MPX controller out of the Driver's door with a Voltage/ohm meter or any other suggestions?

P.S. I am a newbie to Lexus. I inherited my Mother's 2003 LS430 with 75,000 miles on it. It has set in the garage for years with only an occasional run to the store. Any help or suggestions would be greatly appreciated!

 

Mines done that before. Spray the tracks with a little silicone spray and make sure the window is running true and not binding. Grab the glass and see if it moves around.

 

I've done the silicone spray routine. Are you suggesting a thermo fuse overheating or something of that sort?

 

Mine had the exact same problem except it hesitated when trying to go down. The other windows were fine when controlled by the driver's side switch. I replaced the switch and it fixed the problem. I used a pre-owned OEM switch from Ebay for $50.

 

There is no thermo fuse to speak of but the door ECM will kill power to the motor if it draws too many amps. If the window track isn't the issue I'm guessing the regulator motor is on its way out. Are you equipped to do an amp draw test? If so compare it to the other side

 

The motor has a protection device called Positor which protects the motor to be overheated when too much current is going through it. It has the Curie point and it tends to shift to the lower temperature side when aged. Replacing the Positor will fix the problem but the part number is unknown. I'd simply buy one at Akihabara Tokyo. The same thing can be said to many DC motors used for automobiles.

 

Thank You for that. This is exactly what it acts like. I will take an amp draw reading and compare it to the specs!