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View Full Version : What could be causing Intermittent power to the Headlight?



kngpen
07-02-2005, 01:12 AM
I tried the HID relay fix which was no help.
I tried resoldering my LKM which also didnt help
I put a 30 amp fuse in fuse spot #2 and 2 15's in spot 10 and 11 for headlight low beams... no help
Checked the battery today and its "better than average"

I just cant get rid of the intermittent passenger side low beam...
It seems that the actual low beam power wire only gets flashes of power at a time on initial start. I used the electric light bulb checker and hooked it up to the passenger low beam power wire. I turned the headlights on and the checker only flashes once with no constant electricty flowing to it, just like the HID bulb does. To get it to come and stay on, I do a series of on off on off on off till it stays on. Sometimes (once out of the series) neither of them come on, like they share power and the driver's side always hogs it. Finally after 4 mins of doing the on/off the flow of electricity to the bulb is constant and it stays on and I can drive off. OR, if I start to drive usually it will only take a couple flickers to get it to stay on. This is not a bulb or ballast problem as it turns right on when I hook it to the jump starting dock. I am thinking about buying a new LKM as I am getting desparate. What could be causing the lack of constant intial power to be coming to the bulb? I am going to try to put regular bulbs in and see if the lower devouring bulb on the driver's side will save plenty for the passenger side (this is how it appears to work I guess).

uscharalph
07-02-2005, 03:13 AM
I had the same exact problem. ReSoldered the LKM (2X), then needed to replace the right side bulb, so I replaced both.

Paul in NZ
07-02-2005, 05:01 AM
does each side have its own relay in the standard set up????Javier?check the power supply to each side back at the fuse box,i thnk they are fused seperately,maybe you could have a bad connection somewhere.Maybe see if you can swap lkms with someone?

Javier
07-02-2005, 11:43 AM
drawings, it is the same relay for both sides, but different contact. Power gets into the LKM at pin number 2, splits to go to each relay contact (one for left low, and one for right low), go trough contact and then trough monitoring resistor, and finally go out from the LKM at pin 22 towards F11 fuse (for right side).

It is very important to check the fuse, not only switch it, but check the fuse holder contacts, they may be dirty, or overheated (symptom of poor contact or abuse due to higher power rated bulbs). If fuse is find and you can also confirm this by removing LKM and connecting power to pin 22 (Yellow/Blue wire), as right low beam should light up without intermittence, I would carefully check/re-solder al power joints in the path between pin 2 and pin 22 of LKM and finally will check/clean/burnish the relay contacts in the same path.

This is a picture of LKM connector (socket) for pin identification


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



Also this is a similar post


Flickering lights (http://www.bimmer.info/forum/showthread.php?t=10096&highlight=LKM+connector+javier)

Javier

kngpen
07-02-2005, 11:46 AM
drawings, it is the same relay, different contact. Power gets into the LKM at pin number 2, splits to go to each relay contact (one for left low, and one for right low), go trough contact and then trough monitoring resistor, and finally go out from the LKM at pin 22 towards F11 fuse.

It is very important to check the fuse, not only switch it, but check the fuse holder contacts, they may be dirty, or overheated (symptom of poor contact or abuse due to higher power rated bulbs). If fuse is find and you can also confirm this by removing LKM and connecting power to pin 22 (Yellow/Blue wire), as right low beam should light up without intermittence, I would carefully check/re-solder al power joints in the path between pin 2 and pin 22 of LKM and finally will check/clean/burnish the relay contacts in the same path.

This is a picture of LKM connector (socket) for pin identification


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



Also this is a similar post


Flickering lights (http://www.bimmer.info/forum/showthread.php?t=10096&highlight=LKM+connector+javier)

Javier

Thanks Javier, sounds worth a try to resolder the connector :)

Javier
07-02-2005, 12:07 PM
multiple attempts is typical for poor relay contact.

Javier

Edit: It is important to re-solder not only the connector pins at LKM, but also the component leads to the board, along the power path.

kngpen
07-03-2005, 04:57 PM
The problem appears to be fuse area related. I pulled out the fuses and the area looks clean but the metal clamps are a little jiggly. So I put my hand underneath the fuse area and pushed the wires up and put the fuses back in. Lights turned right on (could be lucky tho :).)