electrical problems?

[demi]

I drive a 90 525i, 78k miles. My right licence plate light does not come on and my left fog lights comes on intermittently so I have a display on the instrument cluster to check my licence plate light and fog light(even when the fog light is on). Has anybody experienced this problem before or does anybody has any suggestion as per what to check and do?. thx

[Adnan]

Hi,

Sounds like the infamous LKM problem. This is the light control module that is basically a box full of relays. Over time, the solder joints on the pc board crack, resulting in intermittents.

The LKM is located in the fuse box on the left side, under the hood. Reflow all the joints and hopefully, it should solve the problem.

Regards,
Adnan

[demi]

Thanks for your response. I just changed my LKM. The headlights were on and off and now they work well.The right licence plate refuse to work though while the left fog light will ONLY come on when I start the ignition. However, the right fog light will come on as soon as I turn on the light. Do you think it is still the LKM?.

#2 Do you know the right arrangement of the relays in the fuse compartment?.One relay seem to be missing on the 2 row and when I put it, the wiper began working without control. It stopped when I removed it. Any idea about ths?

[uscharalph]

Yeah the fog light is probably the LKM, but the licence plate light is either the bulb or a wire problem on the trunk arm. Those wire can easily be mangled.

[demi]

so any clue as per how to fix the licence plate wire prob? and do I have to change the LKM again? or re-soldered it?. If resolder, what will I re-solder. I am guessing that I might not have the right LKM.Can this be?

Thanks!

[Adnan]

Hi,

The wires to the trunk are clipped onto the left hinge arm and the flexing back and forth as the trunk is opened and closed, causes wires to break. Lie down in the trunk, facing up and inspect that harness very closely. It's amazing how the wires look intact until you start to poke around.

Solder the broken ones and see if the problem's gone away. This part of things is unrelated to the LKM.

Regards,
Adnan

[demi]

Thanks Adnan. I appreciate your contribution. Any clue about my Fog light problems. They come on BUT the dash says I should check them.I just wired the right one correctly. The guy that had it wired it wrongly - He passed wire from the left side to the right one (Tapped the voltage).

Thanks.

[uscharalph]

Thanks Adnan. I appreciate your contribution. Any clue about my Fog light problems. They come on BUT the dash says I should check them.I just wired the right one correctly. The guy that had it wired it wrongly - He passed wire from the left side to the right one (Tapped the voltage).

Thanks.
Then that's probably why you get the message. The right wire is disconnected. Until you get it fixed properly you're going to get that message.

[Javier]

so guess somebody tap some line to feed the left one, and the original line is still opened having the LKM signaling the CCM to check it (as it doesn't know it is connected elswere).

Javier

[demi]

I have connected it back. There is no open lines any longer BUT The Fog Light still shows on the dash!. Please help if u know anything about this prob!

Thanks Adnan. I have solved the licence plate light prob.!!. I actually found the wire disconnected!

[demi]

Thanks Adnan. I found the wires cut and I have fixed it BUT The F/Fog light still shows on the dash!.


QUOTE=Adnan]Hi,

The wires to the trunk are clipped onto the left hinge arm and the flexing back and forth as the trunk is opened and closed, causes wires to break. Lie down in the trunk, facing up and inspect that harness very closely. It's amazing how the wires look intact until you start to poke around.

Solder the broken ones and see if the problem's gone away. This part of things is unrelated to the LKM.

Regards,
Adnan[/QUOTE]

[Javier]

from pin 16 of LKM connector departs a Yellow/Red wire going to the Left fog light. This and only this wire should be connected to the left fog light.

Use this picture to identify pin.

http://www.bimmer.info/forum/attachment.php?attachmentid=886&stc=1

Javier

Edit: Of course, you can simply check continuty with the fog plug removed.

[demi]

Javier,Thanks for this pic. I will check it out BUT the fog lights come on and the dash still says "F/Fog light".

[Javier]

to the fog lights, they will come on, but as the original feeding circuit is opened, the lamp monitor (LKM) will still believe they are off, as it sees the circuit opened. It has no other way to see the lams are on, than to monitor the circuit current.

Check the wiring as I told you, as there is no reason for the left fog light to come on without turning the ignition key, if you find the wiring adequate, then we will focus in the LKM.

Javier

[demi]

Javier, Thanks.I will check on this.!