Lumbar motor problem
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Joined: Nov 2007
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From: Phoenix AZ
Lumbar motor problem
Hi all,
I've got a C5 and tonight when I got home and shut off the car I noticed a humming and vibration after I shut the car off. Through some investigation I realized it was coming from under the drivers seat, specifically a motor under the seat. I also noticed that when I pushed the buttons for the lumbar control the motor would shut off, when I let the button go it would start running again, so basically backwards. I had just got the car back from the dealer because the trans had to have some work done, though I'm thinking it's not related - not sure how it possibly could be. Anyway, had to pull the seat so I could unplug the motor so it would drain the battery or overhead the motor. I'm lost as to why it's doing this and where to start looking for what's causing it. My only though is the switch for the lumbar control went bad and somehow reversed itself. If anyone has seen anything like this, or would like to offer up some suggestions, it'd be much appreciated!
Thanks,
Bob
I've got a C5 and tonight when I got home and shut off the car I noticed a humming and vibration after I shut the car off. Through some investigation I realized it was coming from under the drivers seat, specifically a motor under the seat. I also noticed that when I pushed the buttons for the lumbar control the motor would shut off, when I let the button go it would start running again, so basically backwards. I had just got the car back from the dealer because the trans had to have some work done, though I'm thinking it's not related - not sure how it possibly could be. Anyway, had to pull the seat so I could unplug the motor so it would drain the battery or overhead the motor. I'm lost as to why it's doing this and where to start looking for what's causing it. My only though is the switch for the lumbar control went bad and somehow reversed itself. If anyone has seen anything like this, or would like to offer up some suggestions, it'd be much appreciated!
Thanks,
Bob
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From: Horncastle Lincolnshire, England
2023 C5 of the Year Finalist - Unmodified
I've heard of a few people who had batteries draining and it turned out to be the seat motor constantly running because of a bad switch. I think you're into a switch change. I wouldn't say it's common but its not the first time.
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Joined: Nov 2007
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From: Phoenix AZ
Hey DeeGee, thanks for the reply. I was thinking thinking the same thing, figured I could swap it with the passanger switch and see if it goes away. Or just check the power that's coming out of it and see if its acting correctly.
Thanks!
Bob
Thanks!
Bob
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Joined: May 2003
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From: East Meadow NY
St. Jude Donor '12
This happened to a friend of mine. Battery was dieing from the motor running constantly.
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From: Horncastle Lincolnshire, England
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Burning Brakes
Joined: Oct 2004
Posts: 931
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From: Rowlett, Texas
I just had mine out yesterday, looking for a non-working bolster bladder.
Turned out to be a broken air tube nipple, but that's another $500 story.
The lumbar electrical controls are pretty complex.
Basically, each of the 3 switches turn the motor on, but also go to a circuit board in a leather pouch way up under the seat. This circuit fires the proper solenoid to direct the vacuum from the pump to the proper bladder.
So, if the vacuum motor is running all the time, it could possibly be any of the 3 switches that is causing the problem. But the schematic shows all three switch wires converging at an "inflate relay" on the circuit board.
So, I bet that relay is stuck on. There is also an inflate pressure switch, controlled by another relay, that cuts the motor off when
pressure is max'd. That may be why the motor stops when you energize one of the switches.
Try this; if each of the 3 switches has the same effect of stopping the motor, then the problem very likely lies in the the circuit board described above. Maybe you could trace down the offending relays and replace (they are soldered in).
If the bladders cost $500, then I bet that little circuit board could be really expensive also.
DG
Turned out to be a broken air tube nipple, but that's another $500 story.
The lumbar electrical controls are pretty complex.
Basically, each of the 3 switches turn the motor on, but also go to a circuit board in a leather pouch way up under the seat. This circuit fires the proper solenoid to direct the vacuum from the pump to the proper bladder.
So, if the vacuum motor is running all the time, it could possibly be any of the 3 switches that is causing the problem. But the schematic shows all three switch wires converging at an "inflate relay" on the circuit board.
So, I bet that relay is stuck on. There is also an inflate pressure switch, controlled by another relay, that cuts the motor off when
pressure is max'd. That may be why the motor stops when you energize one of the switches.
Try this; if each of the 3 switches has the same effect of stopping the motor, then the problem very likely lies in the the circuit board described above. Maybe you could trace down the offending relays and replace (they are soldered in).
If the bladders cost $500, then I bet that little circuit board could be really expensive also.
DG
