Power window/sunroof control unit clicking sound
05-10-2012, 01:15 AM
#1
Instructor
Thread Starter
Power window/sunroof control unit clicking sound
Here's a fun one with a 1990 928.
The control unit under the driver's seat clicks constantly. I mean click-click, click click. Like that of a relay switching on and off. When I do turn the ignition to the on position, the clicking stops. Then the real fun begins. I go to open the driver's side window and the sunroof opens with it. Close it and the same two close as well. The sunroof switch does the same thing. The passenger's side is unaffected.
I changed out the control unit with a NEW one and no change. Checked all the connectors and wiring to the unit and no visual sign of any issues.
Has anyone else had this exact problem?
The control unit under the driver's seat clicks constantly. I mean click-click, click click. Like that of a relay switching on and off. When I do turn the ignition to the on position, the clicking stops. Then the real fun begins. I go to open the driver's side window and the sunroof opens with it. Close it and the same two close as well. The sunroof switch does the same thing. The passenger's side is unaffected.
I changed out the control unit with a NEW one and no change. Checked all the connectors and wiring to the unit and no visual sign of any issues.
Has anyone else had this exact problem?
05-10-2012, 09:39 AM
#3
Instructor
Thread Starter
No Ground Available On Control Unit...
Interesting thought...
When I removed the old power window/sunroof control unit, it was sitting loose under the seat. The new one also has no holes surrounding the box. Generally, when Porsche intends something to be grounded, they would provide a place for this on the box, yes? Also, is there not a ground wire in one of the harnesses that goes to the control unit which then goes to one of the main ground points on the body?
When I removed the old power window/sunroof control unit, it was sitting loose under the seat. The new one also has no holes surrounding the box. Generally, when Porsche intends something to be grounded, they would provide a place for this on the box, yes? Also, is there not a ground wire in one of the harnesses that goes to the control unit which then goes to one of the main ground points on the body?
05-10-2012, 10:32 AM
#6
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If all of the switches work normally, you probably don't have a stuck one...
It isn't unusual for the switches to mechanically hang on the opening in the mounting plate.
It isn't unusual for the switches to mechanically hang on the opening in the mounting plate.
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05-10-2012, 12:00 PM
#8
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When my window switch is stuck (ie: down at either close or open) it will make clicking sound. just tap it so it pops up to the center neutral position.
05-10-2012, 12:06 PM
#9
Instructor
Thread Starter
No, no, it was stated in the post before mine that the switches are not stuck. They just open or close more than one window.
I wanted to know how to correct that. Remember, I do get a constant clicking sound from the control unit "before" turning the ignition on. Once the ignition is "on" then only the driver's side window and sunroof operate together on each others switches. Complete up and down, open and close.
The window and sunroof works fine, just not independent of their switch.
The control unit is NEW and all wiring leading to it is intact.
I wanted to know how to correct that. Remember, I do get a constant clicking sound from the control unit "before" turning the ignition on. Once the ignition is "on" then only the driver's side window and sunroof operate together on each others switches. Complete up and down, open and close.
The window and sunroof works fine, just not independent of their switch.
The control unit is NEW and all wiring leading to it is intact.
05-10-2012, 12:30 PM
#10
Drifting
It could be that someone changed one of the console switches, using the wrong part. Switches for '90+ cars are not compatible with earlier models.
Remove the console side panels which provides access to the console switches connectors and disconnect them one at a time to see if the clicking sound goes away.
Remove the console side panels which provides access to the console switches connectors and disconnect them one at a time to see if the clicking sound goes away.
05-10-2012, 01:23 PM
#11
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I remember having problems related to that. 
Here's an old post (probably to the Rennlist 928 e-mail list) of mine from many years ago and now archived as Nichols TIP #532, quoted here in its entirety (with the "ASCII art" diagrams cleaned up):
Note the comment Anyway, if you open up the .05 switch, you can snip off the part that the brown wire attaches to and effectively turn the .05 switch into a simple SPDT .07 switch. If you do have a mistakenly-used .05 switch in your '90, it's easy to "convert it" to a .07. You just need to break the connection between the "open side" and "close side" switches that the BR wire connects to (see diagram below). IIRC, you have to be careful when disassembling the switch; there are some parts prone to springing out when your first open it up. I seem to recall having the bad luck of having something—a little ball bearing?—disappear down a floor register when I did this the first time. Luckily, I was able to retrieve it.
Here's an old post (probably to the Rennlist 928 e-mail list) of mine from many years ago and now archived as Nichols TIP #532, quoted here in its entirety (with the "ASCII art" diagrams cleaned up):
Power Window Switch Info
Regarding my sunroof and driver's-side window that stopped working...
Took another look at this problem last night. As it turns out, the problem was caused by a replacement switch that I had installed on the passenger side window a week or two ago.
My original passenger side switch was Porsche part number 928.613.123.07. The replacement from 928 International was part number 928.613.123.05 (note the slightly different last digit). These appear to be the same, but there are internal differences that I didn't notice. I should have taken more time to investigate this before installing the replacement.
Anyway, for those of you with my MY (90 S4) or later, take note: the .05 is not a drop-in replacement for the .07. Here are the details: the .07 is a simple SPDT switch. Red wire is common. It momentarily loses to green wire for "window up" and momentarily closes to black wire for "window down".
The .05 has four wires: red, green, black, and brown (I assumed brown wasn't used and otherwise the .05 and .07 were equivalent; I was wrong!) On the .05, the behavior with red/black/green is the same as the .07 above except there is also continuity across green and black unless "window up" or "window down" is pressed. This all seems rather strange until you open up the switch and look at its inner workings. Anyway, if you open up the .05 switch, you can snip off the part that the brown wire attaches to and effectively turn the .05 switch into a simple SPDT .07 switch.
What's really strange is that due to the continuity across black/green that was appearing on my passenger-side window switch (the .05) when it wasn't activated, it caused both the sunroof and the driver's side window motors to always move in the "close" direction regardless of pressing the "open" or "close" ends of their switches. Bizarre! (although probably understandable if you look at the wiring diagrams).
Anyway, the moral of the story is that there is more than one kind of window switch and they are not interchangable. You can convert a .05 to a .07 using the "snip off" technique I mentioned above.
For the record (and the archives), here's the difference between the 928.613.123.05 and 928.613.123.07 window switches. The figures will only look right in a monospaced typeface.
Regarding my sunroof and driver's-side window that stopped working...
Took another look at this problem last night. As it turns out, the problem was caused by a replacement switch that I had installed on the passenger side window a week or two ago.
My original passenger side switch was Porsche part number 928.613.123.07. The replacement from 928 International was part number 928.613.123.05 (note the slightly different last digit). These appear to be the same, but there are internal differences that I didn't notice. I should have taken more time to investigate this before installing the replacement.
Anyway, for those of you with my MY (90 S4) or later, take note: the .05 is not a drop-in replacement for the .07. Here are the details: the .07 is a simple SPDT switch. Red wire is common. It momentarily loses to green wire for "window up" and momentarily closes to black wire for "window down".
The .05 has four wires: red, green, black, and brown (I assumed brown wasn't used and otherwise the .05 and .07 were equivalent; I was wrong!) On the .05, the behavior with red/black/green is the same as the .07 above except there is also continuity across green and black unless "window up" or "window down" is pressed. This all seems rather strange until you open up the switch and look at its inner workings. Anyway, if you open up the .05 switch, you can snip off the part that the brown wire attaches to and effectively turn the .05 switch into a simple SPDT .07 switch.
What's really strange is that due to the continuity across black/green that was appearing on my passenger-side window switch (the .05) when it wasn't activated, it caused both the sunroof and the driver's side window motors to always move in the "close" direction regardless of pressing the "open" or "close" ends of their switches. Bizarre! (although probably understandable if you look at the wiring diagrams).
Anyway, the moral of the story is that there is more than one kind of window switch and they are not interchangable. You can convert a .05 to a .07 using the "snip off" technique I mentioned above.
For the record (and the archives), here's the difference between the 928.613.123.05 and 928.613.123.07 window switches. The figures will only look right in a monospaced typeface.
Code:
928.613.123.05 operates like this (slash and backslash are moving parts):
NC=normally closed switch contacts
NO=normally opened switch contacts
BK=black wire
GN=green wire
RE=red wire
BR=brown wire
(close) (open)
BR
|
|
o-----|-----o
NC / \ NC
BK ------o o------ GN
NO NO
o-----|-----o
|
|
RE
Code:
928.613.123.07 operates like this (slash and backslash are moving parts):
NO=normally opened switch contacts
BK=black wire
GN=green wire
RE=red wire
(close) (open)
/ \
BK ------o o----|----o o------ GN
NO | NO
|
RE
Code:
To convert an .05 to an .07, cut the switch internals at the "X" marks.
(close) (open)
BR
|
|
o--X--|--X--o
NC / \ NC
BK ------o o------ GN
NO NO
o-----|-----o
|
|
RE
05-24-2012, 02:28 AM
#12
Instructor
Thread Starter
Ed:
Thanks for the detailed procedure.
As I removed the side panels to check the number of wires I have for each connector, I have the 3-wire red/black/green switches. So unfortunately that is not my problem.
The switches for the MY 1990 are the correct ones and have never been replaced. The only related item I replaced personally was the window/sunroof control unit for the MY 1990. Does anyone have the correct part no. for this so I can compare?
Thanks for the detailed procedure.
As I removed the side panels to check the number of wires I have for each connector, I have the 3-wire red/black/green switches. So unfortunately that is not my problem.
The switches for the MY 1990 are the correct ones and have never been replaced. The only related item I replaced personally was the window/sunroof control unit for the MY 1990. Does anyone have the correct part no. for this so I can compare?
05-24-2012, 04:04 PM
#13
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Check the harness where it connects to the control unit under the seat. There are two white disconnects a couple of inches before the control unit. One is small in diameter and the other larger about 1/4". The larger one needs to be disconnected. If it is connected it causes some of the symptons you describe. The smaller one is for the express up on the drivers side only. If you disconnect it you will have express up and down on the drivers side window.
When you purchased the replacement control unit was it a different part number to the original part?
When you purchased the replacement control unit was it a different part number to the original part?
__________________
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
George Layton March 2014
928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
George Layton March 2014928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
05-24-2012, 08:15 PM
#14
Instructor
Thread Starter
Roger:
Finally, someone that actually understands my exact symptoms and has a solid simple answer. I was being told some PO must have replaced the switches with the 4-wire ones. I confirmed the factory original wiring and switches are in place and the control unit had been replaced (by me) with an exact part no. replacement of 928 618 040 00 (I took a look at the part number while I was under the seat disconnecting those plugs you specified.)
Could you at least go on to explain what they are there if they only mess up the operation when plugged in. And the reason the express up was disabled by connecting the smaller plug in. I know it is not a factory option as I believe on ly express-down is, but still., why not express-up as well?
I hope everyone above reads this through to the end as there has never been a solution like this offered before for this exact problem in this forum.
Many Thanks. Well done.
Finally, someone that actually understands my exact symptoms and has a solid simple answer. I was being told some PO must have replaced the switches with the 4-wire ones. I confirmed the factory original wiring and switches are in place and the control unit had been replaced (by me) with an exact part no. replacement of 928 618 040 00 (I took a look at the part number while I was under the seat disconnecting those plugs you specified.)
Could you at least go on to explain what they are there if they only mess up the operation when plugged in. And the reason the express up was disabled by connecting the smaller plug in. I know it is not a factory option as I believe on ly express-down is, but still., why not express-up as well?
I hope everyone above reads this through to the end as there has never been a solution like this offered before for this exact problem in this forum.
Many Thanks. Well done.
05-24-2012, 08:44 PM
#15
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Kevin,
You are welcome.
The larger connector I have no clue why it is there only that by connecting it you get issues. Alan our electrons guru probably has an answer.
The express up was not allowed in the USA but used in most other countries where owners were allowed to make their own decisions.
Roger
You are welcome.
The larger connector I have no clue why it is there only that by connecting it you get issues. Alan our electrons guru probably has an answer.
The express up was not allowed in the USA but used in most other countries where owners were allowed to make their own decisions.
Roger