'99 Blazer power window switch block

doubt it's the switch but...assuming you have raised the 4 switch unit up out of the door panel-look at it closely, there are tabs that pry out and also one or some that you insert a fine bladed screwdriver to release the tab. Look at it closely, it does come apart. If it doesn't work, check to see if when you attempt to lower the window that

12 volts are going to one side of the plug that goes on the motor and then 12 volts to the other side of the motor plug depending on whether you push up or down. 12 volts up(on one side), 12 volts down(other wire). good luck snipped-for-privacy@peru-motors.com

tatanka wrote:

Before you do that..... a poster here enlightened me a while back. My 99 Blazer driver window sometimes gets "stuck" in the up position. The solution is to hold the "down" button and slam the door. This has "fixed" my problem every time it happens so far. Thanx to whoever first suggested it. Mike

Back to this problem...

The window started working again all on it's own, then quit again a few weeks ago. The door slamming trick didn't work. A "new" (used, from eBay) switch block had the exact same symptoms. I took the inside panel off the door expecting that I might find a limit switch or something, but there doesn't appear to be one. Reseated all of the connectors, still no joy. I measured the voltage at the motor connector and get "zero" in either the up or down position, so there's no power at the motor. The other three windows still work fine.

Wish I had a schematic.

Anyone out there have an idea what the problem might be? What is it that determines that the window is "full up" or "full down?"

Thanks for any ideas! (And apologies if I've duplicated this post)

Does that thing have "the rapid express down feature" ie......one touch and the window goes down by itself?

Stan

Check for power at the switch. This sounds like a power problem. I have a 89 that I have had since new and I had trouble with drivers side window once, it turned out to be the switch.

----------------- TheSnoMan.com

Bad brushes in the motor (common)OR the rear bushing in the motor is failing allowing the rotor to drop and not contact the brushes correctly (not real common but it happens). Or it could be a bad connection on the motor OR a failing wiring harness.

Yes, it does have the "Auto" down feature.

This worked on my 4th gen Firebird...... Remove the express down module and bypass it.

Mine was located on the firewall, INSIDE, just in front of the hump. The plug has 4 wires and 1 blank space in it. Left to right.......Blue/Empty/LT.Brown/DK.Brown/Gray

I jumpered the Dk.Brown to the Gray.

The reason was I didn't want the express down feature..... I have learned if the unit/relay burns out....the driver's window won't work.

Just a thought to look at.

Stan

Good clue. Thanks!!