Bill Ball

EDIT 10/20/08: Unless you want to see an electrical donkey chasing his tail I suggest that after reading this post you just skip to post #132 and take it from there.

Here's a good one.

This 90 S4 sat for a month or so with the battery ground detached. I re-attached it and the passenger window immediately went down.

I can move it back up with the window switch, but it will immediately go back down as soon as I release the switch. The only thing that will stop it from going back down is to detach the battery ground or pull the plugs to the window controller box that resides under the driver seat.

I swapped window controller box with no change in this behavior. I doubt it's the controller box, as 2 of them do the same thing and neither did that before. I did have a problem before with the controller boxes relay appearing to stay latched after the ignition was shut off and the door opened and was draining 150ma. That seemed to be resolved somehow, but maybe that is a clue. The door pin switches seem to work otherwise. Also, the driver side window is not affected.

If I pull the window switch plug, it still goes down. So, it's not the switch.



I've attached the relevant wiring diagram--1st pic shows passenger side, then other shows driver. The relevant wires from the passenger side motor go to pins 3 and 5 on the right side of the controller. The driver side shared pin 5 but goes to pin 4. So, I'm banking on something affecting the wire that goes to pin 3.

Alan

Bill - with the switch in circuit - test the voltages on the connector for the switch:

What is voltage on the Red, Black & Green wires - at rest and with the switch in the Up and Down positions?

I suspect there is a some resistance on the center switch position that is overriding the bias resistor inside the window controller...

Report out on the voltages and it should be obvious.

Also - If you pull the controller what resistance to ground and or B+ do you see on pin 21 (Red wire) of the controller connector.

Alan

Bill Ball

Thanks for the test ideas, Alan. I'll be getting back to it this afternoon.

Bill Ball

Alan, et al:

Here are the results.

Passenger switch voltages
-------------RED-----BLACK-----GREEN
Neutral+++ 0+++7.2/4.5+++10.85
Up+++++5.29++ 7.2/4.5+++ 5.7
Dn+++++4.5++++4.5++++ 10.85

The black pin gave me 7.2 volts initially, then 4.5. Couldn't quite identify why it changed in those 2 positions. Note the battery was not fully charged. Ignition was off, key out. Doors open.

Pin 21 red wire was 0 ohms to ground.

It's Greek to me. Hope it means something to you!

worf928

Those voltages are wacked. Since the window goes down with two different controllers and goes down when the switch is disconnected from the circuit then I have to think the problem is between the plug to the controller and the fuse panel.

Just to make sure of that theory, I might disconnect the door harness under the parcel shelf and use two jumper wires to connect only the circuit to the window lifter. If the window still goes down no matter what then the problem-between-the-controller-and fuse-panel theory is correct. If the window doesn't go down then there's a harness problem between the controller and the lifter and its probably where the door harness flexes whenever the door is opened.

But, Alan's the electrical genius so I'm just going to

Bill Ball

Dave:

I tend to agree. The window will go down with the switch disconnected. The only thing that stops it is to disconnect the controller power supply. I think Alan recognized that but was asking that the voltages be collected at the switch for some diagnostic purpose. Like I said, it's Greek to me.

I forgot to mention that the voltages at the switch were the same whether the ignition was on or not. With the ignition off the switch is inactive (once the door is opened).

worf928

Yup. The switch is a (somewhat) convenient test point.

Bill Ball

Alan? Any feedback on my voltage values? I'm flying blind on this.

Additional clue: As soon as I plug in the large white plug, which is pins 31-38, the window starts down, ignition off.

the flyin' scotsman

Bill have you done any resistance checks of the wiring between the switch to the controller and the wiring from the controller to the door? I'm thinking you got a pinched wire to ground.

the flyin' scotsman

For a baseline I checked the voltages at the passenger switch my car; igntion off from the brown ground wire 0 volts at both the green, black and red wires...........switch in neutral position.

Power on, switch in neutral.........brown to balck and green, zero volts; brown to red +12v
Power on, switch in down position........brown to green, zero volts; brown to black and red +10v

Alan

Dave appears to be completely correct - those voltages are whacked!

Bill are you saying that you get these voltage readings and the window goes down when the ignition is off & door open?

... and also does this even with just the white plug installed?

If I understand correctly you have the exact same behaviour on both window controllers also...?

If this is really the case you should probably shoot both window controllers just to be safe...

This sounded so much like a switch wiring leakage problems (resistance to ground maybe) - however your results suggest not.

If the black plug is disconnected then the passenger switch wiring is not connected to the controller at all. This implies a fault with the controller (unlikely in 2) or with the wiring from the controller to the motor

Test the white plug connections 33 and 35 - do either one show any low resistance (<than megohms) to 12v battery or ground - don't need to test between them...

Alan

Bill Ball

I understand the voltages are whacked. Note that the window motor is still powered while I am measuring. If I leave the controller white plug attached overnight, the battery is drained. So, some kind of short somewhere.

Alan - 33 and 35 are in continuity with ground. I see that these go to the motor. So, that's strange. I need to get at plug T22 in the passenger door and check both sides. Thanks for that idea, Alan.

Further clue: If I plug in the brown and black smaller plugs and plug in the white plug cocked so that the end with pin 34/38 is not seated fully, the window will not go down spontaneously, but I can make it go up with the switch.

Mrmerlin

Bill after reading this is there a realy for the windows ? One with the delay in it ,why not try taking this relay out and cleaning the internal contacts? Also does the CE pane look like it got wet ? Possibly just before this happened?
If it did get wet then i would suggest that you check all of the relays , by removing them one at a time (shake each one looking for water) and also checking for the correct part number any relay with corroded terminals should be opened, This task is done with the batt disconnected of course

Bill Ball

Hi Stan:

The relay is in the controller. I have a brand new controller as well as the original one. There is no difference in behavior. BUT...I'm going to pull the CE panel, as you suggest. There have been enough electrical issues that I need to check it over.

Alan

Bill - I think the issue is with the motor wiring to/in the door.

I'd suggest opening up the door - disconnect the motor and ohm out the wiring back to the controller plug with controller & motor out these wires should not connect to anything - seems they are shorted somehow - check out the flex points....

Alan