So the other day my uplander rear quarter panels on both sides opted to not open, After I closed them using the overhead switch.

So I began digging into why this happened. I removed the trim and accessed both window regulator motors. Removed both rear quarter panel units and tested with a 12v battery.
Both operated normally.

I took a 12v led and fed it into the connector, same for the other side, I just switched the polarity for the led on the other side. The led lit up on each side as I pressed open/close up/down

After some probing and fuse pulling from the passenger side fuse box I had discovered the ELC fuse location #2 was providing that yellow line with power.
So I reconnected one of the window regulator motors to the rear window connector. What I found out was.. The +12v was zero once a load greater then a led was placed on that circuit.
So I grabbed another jump wire and I found another +12v line from the driver/passenger overhead lighting circuit (orange) and tapped that into the yellow +12v and what ya know...
The window motor worked. Both directions.

So.. Why is the ELC providing +12v on a 20A fuse, Yet it can not support the motor load... I'm puzzled at this and wondering if any one else may have a good place to get a proper wiring schematic as I bought on off ebay and its not overly detailed for my needs.

The Tan/Black lines are to both window regulators.
Yellow and Black are +12v for the windows, Gray is backlight lumination, white. No idea

The black 3 pin connector is to the overhead lights for passenger / driver that I used for the test (orange)

Trying to figure out if that ELC has a relay and why it would opt to stop providing +12v on load.

I can bypass the ELC and use the overhead +12v to make the rear vent windows work again. I'm after the cause/fault.

 

So I started removing the trim from the floor on the rear passenger side and passenger side. Found some green corrosion on a yellow line to two smaller yellow lines.

Cleaned it up. Rear vent motors started working again.