I have a BMW Z4 2003 E85.
I plug the LHS head light into the car the Running lights come on for 25 seconds then turn off. Then a fault light in the dash appears telling me I have a light out.
Initially I thought it was a fault with the earth as both lights share a common earth. But…
1) The blinkers work (a shared function) for these light bulbs.
2) On the work bench the running lights - installed in the head light - work fine
3) Power and earth seem to check out on the car side of the BMW headlight plug.
With some make shift wiring to assist my fault finding efforts.
4) By passing the BMW headlight plug and ONLY connecting the running lights in the head light from the car wires - they turn on and stay on.
5) If I un plug all my make shift wires and plug the head light back into the car the Running lights come on for 25 seconds then turn off. When the running lights go off the Fault light in the dash comes on.
The LHS running lights will not turn back on again unless all wiring has been disconnected, the ignition turned off, all wiring reconnected. Then when I turn the light switch back on, the running lights turn back on for 25 seconds and then turn off again. Every time I repeat this process I can once again achieve running the LHS running lights for 25 seconds before they turn off. No fuses trip.
6) I have plugged the LHS head light into the right hand side Headlight plug and the running lights work fine.
7) I have swapped out the interior headlight switch. The fault remains.
My thoughts are –
After the 25 seconds of illumination the BMW system is tuning them off registering a fault somewhere.
Does anyone know of why the lights would illuminate for 25 seconds then switch off?
I am thinking that it must be a test function of some sort and something fails somewhere.
Any suggestions would be greatly appreciated.
I plug the LHS head light into the car the Running lights come on for 25 seconds then turn off. Then a fault light in the dash appears telling me I have a light out.
Initially I thought it was a fault with the earth as both lights share a common earth. But…
1) The blinkers work (a shared function) for these light bulbs.
2) On the work bench the running lights - installed in the head light - work fine
3) Power and earth seem to check out on the car side of the BMW headlight plug.
With some make shift wiring to assist my fault finding efforts.
4) By passing the BMW headlight plug and ONLY connecting the running lights in the head light from the car wires - they turn on and stay on.
5) If I un plug all my make shift wires and plug the head light back into the car the Running lights come on for 25 seconds then turn off. When the running lights go off the Fault light in the dash comes on.
The LHS running lights will not turn back on again unless all wiring has been disconnected, the ignition turned off, all wiring reconnected. Then when I turn the light switch back on, the running lights turn back on for 25 seconds and then turn off again. Every time I repeat this process I can once again achieve running the LHS running lights for 25 seconds before they turn off. No fuses trip.
6) I have plugged the LHS head light into the right hand side Headlight plug and the running lights work fine.
7) I have swapped out the interior headlight switch. The fault remains.
My thoughts are –
After the 25 seconds of illumination the BMW system is tuning them off registering a fault somewhere.
Does anyone know of why the lights would illuminate for 25 seconds then switch off?
I am thinking that it must be a test function of some sort and something fails somewhere.
Any suggestions would be greatly appreciated.