M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => Electrical => Topic started by: Rafiki on February 12, 2009, 10:42:17 PM
-
The 15amp fuse to my windows blows almost every single time i turn the car on and off.
any idea where it would be coming from?
im assuming its a bad ground somewhere. but i have no idea where
-
Check both the L & R door harnesses that are enclosed inside of the rubber conduit that is between the door and the A-pillar. This is a very common "fail" area, as the wires within that conduit are constantly "bent" many many many times when opening and closing the doors through out the years. Due to the age of these vehicles, the wires can crack or break, or the exterior wire casings could crack off, exposing individual bare wires inside of the conduit (of which you cannot see through) and those wires could be touching other exposed wires or metal, causing a short, which is causing blown fuses.
-
Could also be the window motor mate
-
Check both the L & R door harnesses that are enclosed inside of the rubber conduit that is between the door and the A-pillar. This is a very common "fail" area, as the wires within that conduit are constantly "bent" many many many times when opening and closing the doors through out the years. Due to the age of these vehicles, the wires can crack or break, or the exterior wire casings could crack off, exposing individual bare wires inside of the conduit (of which you cannot see through) and those wires could be touching other exposed wires or metal, causing a short, which is causing blown fuses.
thanks a lot. those conduits are in good shape, could that wirse still be bad under them?
-
Yer mate its a common prob on the E30 and the E36
-
I had a problem blowing the fuse when the right rear door window was operated from the center console switch. Switch was bad internally. Your problem sound more, ah, systemic (love the sound of that word...), but the switches can blow the fuse.
Good luck.
-
I had a problem blowing the fuse when the right rear door window was operated from the center console switch. Switch was bad internally. Your problem sound more, ah, systemic (love the sound of that word...), but the switches can blow the fuse.
Good luck.
well i figured out that the problem is not coming from my drivers window. Only when i lower/ raise my passenger window.
you guys said you could be the switch itself?
i was going to take the doorcard off and check out the motor and anything.
but its it could be the switch, hell, ill change it out tomorrow
thanks!
-
im assuming its a bad ground somewhere. but i have no idea where
If you're blowing a fuse I'd say that you have a great ground somewhere. :)
-
The 15amp fuse to my windows blows almost every single time i turn the car on and off.
I'm looking at the ETM and it shows a 30amp fuse in spot 17 that is in series with the 25amp circuit breaker.
You might want to try putting a 30amp fuse in spot 17 as it shows in the ETM.
Then I would disconnect both window switches and try turning on the car. If it still blows you have a short to ground between the fuse and switch connectors.
If it didn't blow, plug in one of the switches and try it. If it blows then the problem is in the circuit for that window. Repeat for the other window as necessary.
-
the problem is the passenger side window. anytime i open or close it, the fuse blows. But it doesnt blow until the window is all the way up, or all the way down. its weird.
what exactly do you mean by the problem being in the circuit for the window? what should i follow?
-
I'm assuming you have a two door?
First I would check your fuse, the ETM shows that fuse #17 should be a 30 amp fuse and you said you have a 15 amp fuse in place.
The system is setup so that the 30 amp fuse is in series with the 25 amp circuit breaker. The circuit breaker should trip before the fuse blows.
The circuit is laid out like this:
Unloader relay K5
-Fuse 17 - 30 amp
--Power window circuit breaker - 25 amp
---Splice S322
----Left window switch
-----Left window motor
----Right window switch
-----Right window motor
The left and right window are powered from the same source and are connected together at splice S322.
Your original post said that the fuse blew when you turned the car on and off, but later you said that it blew when you operated the window, that's a slightly different deal.
Assuming the fuse blew every time you turned the CAR on and off you could narrow down where the problem was by removing switches. If you remove the power window switches, you've isolated the power window circuit after the switches.
If the fuse blew with the switches removed, then you would know that the problem (a short to ground) was somewhere between fuse 17 and either of the two power window switch connectors.
If the fuse did not blow, then you could install one of the switches and try again. If the fuse blows then you know the problem is in the switch or the circuit after the switch on that side. Then to make sure it wasn't the switch, you could install the other switch into the "bad" window and try again, that would tell you if the switch is bad.
Hope that makes sense.
Now, having said all that, you're problem is with one window in particular. First check the fuse, the ETM says it should be a 30 amp, not a 15 amp.
If that doesn't fix it, take the switch from the driver's side and put it in the passenger side and try it again. That will eliminate the switch as a problem point.
If the fuse still blows, remove the switch, get an ohmmeter and connect it from pin 8 of the window switch connector to ground, you should get something greater than 0, in fact it should be an open or very high resistance. (It takes 0.4 ohms to make 30 amps and 0.8 ohms to make 15 amps at 12 volts.) Repeat with pin 1 to ground and again you should get something greater than 0.
If you get 0 or very low resistance on either of these wires then you have a short to ground and you need to start looking for where those wires are rubbing on something and making a ground.
Let us know what you find.
-
will do. i really appriciate it. Ill work on it tomorrow. thanks again.
-
Now, having said all that, you're problem is with one window in particular. First check the fuse, the ETM says it should be a 30 amp, not a 15 amp.
If that doesn't fix it, take the switch from the driver's side and put it in the passenger side and try it again. That will eliminate the switch as a problem point.
If the fuse still blows, remove the switch, get an ohmmeter and connect it from pin 8 of the window switch connector to ground, you should get something greater than 0, in fact it should be an open or very high resistance. (It takes 0.4 ohms to make 30 amps and 0.8 ohms to make 15 amps at 12 volts.) Repeat with pin 1 to ground and again you should get something greater than 0.
If you get 0 or very low resistance on either of these wires then you have a short to ground and you need to start looking for where those wires are rubbing on something and making a ground.
Let us know what you find.
I couldnt wait until tomorrow.
but, everything works perfect now!
And I meant the fuse was blowing when the windows would go up or down. I had a 15amp in spot 17. That was the problem for sure. I went ahead brought out the ohm meter and checked everything you said. And everything checked out and was exactly what you said it would be.
The privious owner had just replaced the fuse with a 15amp everytime it went out. And he gave me like 20,000 extra 15amp fuses when I bought the car. So for some reason I just assumed it was a 15amp.
I appriciate the help, and will pass on the knowledge. Thanks again.
-
Good news! The simple fixes are always the best.