Rear Quarter Windows not getting Full Voltage

Hello,

I have a 2000 Chevy Venture, extended wheelbase.

Over the winter, the Automatic Rear Air Leveling Compressor stopped working. If I manually jumper the relay contacts, the compressor kicks on. I replaced the axle-mounted sensor and the relay, but the compressor still doesn't come in automatically. So I gave up on it.

Now that the warmer months are here, I tried to open the rear quarter windows. But now they don't work. :shakehead
Last night, I opened up the trim covers and removed the connectors from the motors. When activated, they only get +1.5V or -1.5V, depending on how you flip the switch.

I was searching for more information and found this thread:
http://www.automotiveforums.com/vbulletin/showthread.php?t=227145

Not sure if resurrecting older threads is frowned upon, so I just referrenced it. But I am having the exact same symptoms. The Automatic Rear Air Leveling Compressor stopped working probably at the same time as both rear quarter windows stopped working. The fuses are OK. I measured them with an ohmmeter to make sure. (I even verified key-controlled 12V on the contacts.) Also, as the above thread states, "The little solenoid in the rear for the accessory air clicks on and off with the switch".

I was wondering if anyone resolved this. Lesterl suggested "Have you checked the pass thru connector in the floor board". Exactly what/where is that?
According to this schematic, that connector is not even involved:
http://www.my-chevy-venture.com/images/Rear-Power-Windows-sch.gif

Any other ideas? The A/C does not hold a charge, and the kids are roasting without the rear windows being 'open-able'. Thank you.

FIXED!!

The two failed circuits are definitely related. For future reference, here is the solution:

Remove the RH (passenger) front kickpanel and sill plate. These are plastic, and just pop off. Now peel back the carpeting some, it doesn't take much. You will see a large bundle of wires coming from behind the fuse panel. You can't miss them, the bundle is >1" diameter. The wires then run towards the rear of the van (under the sill plate), and branches off underneath the seat. Unwrap the factory "tape" used to hold the bundle together. There was a coating of moisture, rust, and dirt on the insulation of the wires, but relatively harmless overall. The problem wires are the ones that are spliced at the factory. Flatten the bundle of wires in your hand and spread them apart a little with your fingers. You will see some wires that go into a watertight wrapping. They go in as one, and come out as two. The problem is that once water eventually penetrates into the watertight wrapping, it can't get out. So the joint corrodes until the connection breaks. On my van, the joint that was bad had one #18 AWG yellow wire going in and two #22 AWG yellow wires going out. (I did check the other splices, but they were not corroded.) So I cut-back the wires and soldered them together using a new piece of wire.

The copper conductor underneath the old wire's insulation was still corroded, no matter how far I cut it back. So I used a trick I read about elsewhere. Take a small container (I used a tiny baby food jar) and fill it with fresh vinegar. The more acidic the better. Then take your stripped wire, and bend it to go into the jar. Allow to soak 10~30 minutes. The wire should now be tinnable. Anyway, after soldering the wires together, I had forgotten that I left the keys in the ignition. About a minute later, I had the pleasant surprise of hearing the rear compressor kick on! I then tried the rear quarter windows, and they work too!

I sealed the new splies up as best I could with vinyl electrical tape, but adhesive-walled heat shrink tubing would've been better. I also re-tested all the other electrical switches (door locks, etc) before re-assembly just to be sure I didn't pull some other wire out.

Help this helps someone!