I am having an issue with the passenger low beam headlight on my 2000 S40. About two weeks ago it went out and I can not get it back on. I have confirmed that it is not the buld, confirmed that the fuse has 12 volts supplied on the high side (also, it is not blown). On the breakout from the body harness where it attaches to the headlamp unit the voltage is ranging from 11 - 4.5 volts. The voltage varies and sometimes you can actually see it drop! I also checked the connection within the headlamp from the harness to the bulb and that is fine.

I tried to ping the low side of the fuse to the end of the harness and there is nothing. I am assuming that there is a relay in there somewhere (thus the connection to ping is not complete) but can not find it. At this point I am thinking that, if there is a relay that controls the lights, that it is faulty. I have a Haynes but it is the 1999 English variety thus I am not sure what in the architecture is carryover.

I have gone through the relays under the IP but didn't seem to find one that controls the headlights (as noted by the driver side never going out when I was pulling them).

I was wondering if anyone has had a similar issue out there?