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92 Astro Pass. Power Window - Weird Issue

9K views 3 replies 4 participants last post by  Phantom 
#1 ·
Hi All:

I've done some searches on the forums and it seems some other people have had similar problems as I'm having, but nothing exactly like my symptoms.

I've got a 92 Astro with power windows and I've been trying to get my passenger side to work properly. Having some strange problems. Here's what I've done so far:

1) I've repaired all the wiring in the passenger door boot. Spliced in new wiring to repair broken wires.
2) I've tested all the power window wires on the passenger side with a multi-meter and I'm getting the appropriate power and the grounding is OK
3) I've replaced the power window motor with a brand new unit.
4) I've replaced the passenger side window switch with a new switch.

My symptoms:
1) After fixing all of the above, I noticed that the window motor would engage for "UP" but not "Down"
2) I could make the window go down by bypassing the switch with some leads (indicating the window motor works properly and the problem was with the switch)
3) I replaced the passenger window switch a 2nd time with another new switch and the window worked for 1 day.
4) After initially working for a very short time, the switch seems to have failed again and the window will no longer go down, only up.

Could I be burning the passenger window switch out somehow? I can't think of any reason that 2 brand new switches would fail the exact same way. Has anyone had the same problem or knows what might be happening? I don't see any shorts or overloads with the multi-meter so I'm really confused.

Thanks in advance!
Andrew
 
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#2 ·
This is my 89. Perhaps the same as your 92.



Sounds like you've got a handle on all the steps that seem logical to troubleshoot.

I suspect the passenger side switch. If I read your description correctly, your tests reveal
everything is correct up TO the switch, and you can engage the motor both directions AFTER the switch.

I suggest caution when applying bypass power and ground when the switch is connected.
Note in the schematic that when the switch is at rest, BOTH terminals are grounded.
If you apply + and - power to the switch, the + power will short to ground (blk wire on
the driver side switch in the diagram).

For the same reason, there should not be any GROUND connections to the body of the
passenger door from the harness. GROUND is "supplied" (enabled) by the TAN or the
DK BLU/WHI wires coming from the driver side.

If you haven't already -
Unplug the passenger side switch entirely. Then on the harness/connector coming from
the driver side, through the door jam, probe to find +12v on pink and ground on
both TAN and DK BLU/WHI.

For the most part, that verifies that it's wired correctly
from driver side to passenger side. HOWEVER - If one of those three wires is compromised
(worn thin somewhere) it may TEST ok but then not be able to carry the higher current
needed to power the motor. ie the TAN wire (down wire) might be able to carry the miniscule amount of
current needed for your DVM to read continuity to ground. But once it's required to carry
the amperage needed for the motor, it fails.

If all of that passes-

Test the motor with nothing connected. It's DC (obviously) and reversable. Apply + and - 12v to
the terminals then reverse. If motor works both ways, it's ok. Now try doing the same thing but
using the wires FROM THE HARNESS to supply that + and - voltage. Use PINK for + and use either
TAN or DK BLU/WHI for -. Do that in both directions as well. Use TAN for - then use DK BLU/WHI for -.
Do all of this with the passenger side switch OUT of the loop - completely disconnected.

If all of that passes -

Test the driver side switch for the passenger window. You'll need a helper human for this.
While the helper activates the switch to UP, you apply the DK BLU/WHI wire to one of the
motor terminals. Apply the TAN wire to the other terminal. If the motor moves then leave
them connected and have your helper activate the switch to DOWN. The motor should reverse.

If all of that passes -
Then it's pretty certain that the motor is OK (that's the easiest part to test)
and that the wiring in the harness is OK. At that point, I'd suspect the passenger side switch.

Lump
 
#3 ·
Could there be a bad connection in the connector that goes to the switch?
Put a meter on it and check for voltage on the wire that is for down right before the connector , if there is voltage right before the connector but the window doesn't go down bad connector
 
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