Good Afternoon Everyone,

I just completed "The Big Fix" on my 1989 245 with 245,000mi. Something unusual has happened to my driver side headlight; It seems as though the low beam is receiving no power, the high beam is fine, bulbs and fuse has been changed along with the headlight relay.

There is power at both 87a & 87b of the relay; going through my wiring diagram, the blue wire (Low Beam Hot) seems to somehow go to the "Bulb out relay".

The bulb out relay has juice on the passenger side headlamp, but none on the drivers side.

Is the headlight driven before the bulb out relay or is it backfed after the headlight?

Could the Bulb out relay be causing the Headlight to not work?

Thank you in advance for all your help.

Mark
Recently rehabbed 1989 245 (245,000) New suspension bushings, New Struts & Shocks, Front oil seals, New Timing Belt & Tensioner, New Motor mounts, New Transmission mount, New Rear Trans bushing & Seal, New Center Support Bearing, New Fuel Pumps, Filter, & Relay, New Overdrive Relay, New Rotors & Pads, New Front Wheel Bearings, New Water Pump, New Air Mass Meter, Full Tune Up, Cleaned Throttle Body & Idle air Motor, Hella aux. Low Beams, Hella Driving Lights, Rebuilt front seats, All fluids flushed, and ready to go another 245,000.

The bulb failure relay can be the cause. The power has to go through this before it gets to the two lamps.
The relay uses two small coils to compare current for the two circuits- if there's an imbalance it turns on the output, the warning light. This applies to all of the circuits it monitors. (A bunch.)

I'd start there, get a used relay and just plug it in. It's a big red can under the dash as you probably know. They can be popped open and re-soldered, if that is indeed the problem, but circuit board space inside is tight and repairs might be sort of tedious. A used one should be $10 or less at a junkyard.

Good luck!
--
Rob Bareiss, New London CT ::: '87 244DL/M47- 230K, 88 744GLE- 220K, 82 245T-181K Also responsible for the care and feeding of: 88 745GLE, 231K, 87 244DL, 239K, 94 855GLT 189K