Was driving to work this morning when, without warning, my driver's side window began dipping and then going back up completely at random, like it does normally when you're opening the door. Door was completely closed/locked. The dome light was also on, but the door was definitely closed. When I to work, I confirmed the door was completely closed and locked the car. Dome light went out, but the window continued to go slightly down and back up completely at random, sometimes going a full minute or more before cycling again. It's raining, so I ended up having to disconnect the battery to keep the window fully up.

It sounds like a door sensor malfunction to me, but I'm not too familiar with Minis and I've never had a car with the window Dipper function. Any ideas?

 

How old is the battery?
When funny electrical things start happening to MINIs, the first place to look is the battery.

 

It's a 2006 Cooper S, 87k miles, manual trans.

Battery doesn't have a date stamp on it but has shown no signs of acting up and has no corrosion. Looks fairly new, but you can't really go by that with an enclosed battery like the Minis have.

 

Check engine and battery grounds for security?

 

Gave the grounds a good looking over and they all appear to be clean and secure.

 

Check the passenger side carpet for dampness? The BC1 module is mounted down there and often gets flooded from a loose sunroof drain, or a leak around the windshield/firewall.

Other than that, I would check the battery again. Many posts I've read had the electrical problems clear up even though the battery appears to start the car without a problem.

 

First off, thanks everyone for your help so far, it's greatly appreciated.

Checked, no dampness, everything looks clean and good. I double checked the battery leads and reconnected the battery and the problem's still there. Will the battery test as being bad? I don't have a problem replacing it, but I'd rather not spend $150 if I don't have to.

 

That seems to be the problem with MINI's from other posts I've read. The batteries seem to be good, test as good, but the problems seem to be fixed with a new battery.

How old is your battery? Maybe it's time to replace it if it's 4 years, or more. Some people will wait for the battery to go bad, but some don't want to deal with the inconvenience of getting stuck with a dead battery someplace.

 

Tested the battery with a multimeter and I'm getting 12.63v, so I'm leaning toward it not being the battery. I'm going to take a closer look at the body control module when I get home and see if it's looking OK.

 

Just keep your eyes out for any other gremlin type peculiar behavior in other electronics systems. If something else starts acting weird then regardless of your multimeter, its the battery.

 

Reach behind the switch panel...make sure it is plugged in tight...
Also do you have a "auto-up" window circuit installed...it's aftermarket, and might have failed.

To re-initialize the window dipping...if I recall right, just hold the switch in the up position for a few seconds...if I recall, more than 8...might help...
I might suggest you look around...for a cut or rub in the wiring...maybe where it goes in and out if the door?

 

Checked the BCM last night, dry as a bone despite it raining all day, looked perfect. Plugged everything back up again and no window issue. Guess I have to wait and see if it comes back now.

 

Good deal. Even so, next time it starts doing funny electrical stuff, suspect the battery/alternator system first.

 

Problem came back today. Replaced the battery, didn't solve the issue. Now I've got the door panel off, looking for wiring problems. I found some aftermarket speakers and some sort of audio crossover which was pretty corroded. Haven't found any wiring issues other than that, yet.

 

The window dipping and dome light coming on suggests to me that the car thinks the door is open, even though it is mechanically closed. I'd look at the switches in the door jamb which tell the computer the door is closed, and check their connections.