leccy window fuses keep blowing

Post Thu Jul 21, 2005 6:12 pm

hi guys, ive got a window fault

they keep blowing fuses, both the normal one and the one that lets you put them up with the key out and door open. theres no pattern to them blowing, its just randomly, sometimes they last a few days other times its a few minutes. anyone got any suggestions as to what the problem could be? ive checked the pillar connections and they seem fine

cheers in advance

stevo

oh its an m40 318i

Post Thu Jul 21, 2005 6:50 pm

make sure your using the right fuse to start with

http://www.e30zone.co.uk/modules.php?na ... 0fuses.htm

other than that i dunno mate

Post Thu Jul 21, 2005 9:38 pm

jamesroools wrote:make sure your using the right fuse to start with
http://www.e30zone.co.uk/modules.php?na ... 0fuses.htm

other than that i dunno mate

checked that, i even replaced all the 10amp ones with the proper 7.5amp fuses stated in the owners handbook

cheers anyway dude

Post Thu Jul 21, 2005 9:46 pm

could be a bit of water/moisture in the doors causing the window electrics to short out

Post Fri Jul 22, 2005 12:14 am

jamesroools wrote:could be a bit of water/moisture in the doors causing the window electrics to short out

Electrics wouldn't short out if the whole door was underwater.
First question - Do the fuse(s) blow if the window switches are not touched, or only when the windows are moving?
2nd question - Do you have an electric roof?
3rd question - Electric windows on rear doors? If four door of course.

Post Fri Jul 22, 2005 9:20 am

Do they still work when the door is open. I had this problem on my 320i cab, and all I did was replace the cut off switch on the centre console (the one that stops the windows working for kids etc) after I had replaced this they worked like a treat again

Post Sat Jul 23, 2005 3:33 pm

Brianmoooore wrote:
jamesroools wrote:could be a bit of water/moisture in the doors causing the window electrics to short out
Electrics wouldn't short out if the whole door was underwater.
First question - Do the fuse(s) blow if the window switches are not touched, or only when the windows are moving?
2nd question - Do you have an electric roof?
3rd question - Electric windows on rear doors? If four door of course.

they dont blow when the windows moving, i usually find they go down then wont go back up
no electric roof or electric rear windows

cheers

Post Sat Jul 23, 2005 3:54 pm

So do you think the fuse blows when you push the up button? If so, is it only the driver's window?

Post Sat Jul 23, 2005 4:03 pm

Brianmoooore wrote:So do you think the fuse blows when you push the up button? If so, is it only the driver's window?

could be actually, i think its the passenger side that blows the fuse.
i'll check it out

thanks guys:thumb:

Post Sat Jul 23, 2005 8:21 pm

A window motor has two wires, one blue and one black.
If the black wire is earthed and 12V+ applied to the blue, then the window goes down.
conversley, if the blue wire is earthed and 12V+ applied to the black wire, then the window goes up. Fairly sure this is the right way around.
The wire that becomes live when you press the passenger window up switch is a purple wire from pin 1 of the passenger window switch to the blue wire in the passenger door motor. Somewhere along it's length the insulation of this wire is damaged and shorting to earth.
Other less likely possibilities are a fault in the window switch itself or in the motor.
Take the passenger door card off and pull the plug on the motor to eliminate it.
First thing I would do is prise out the passenger window switch and unplug it for a week or two, just to check that the fuse blowing stops.

Post Sat Jul 23, 2005 8:49 pm

cheers brian

the switches do feel a bit rickety, might replace them anyway. does anyone know how much new ones are?