My 1991 240 sedan has no power to headlights and no dash lights when the headlight switch is in the headlights-on position. High beams come on momentarily in the flash mode. Parking lights and dash lights come on when headlight switch is in that position.
Thanks to other threads, I found the headlight relay in the center console, contrary to what Mitchell's 1991 locater says. Terminal numbers on the headlight relay agree with wiring diagram but wire colors do not. There is no power on the yellow wire in the step relay when the key switch and headlight switch are on. There is no yellow wire going to the headlight relay, contrary to what Mitchell and Haynes show. Headlight relay has the following terminals and wire colors:
30 - Blue/red
87 - white
86 - Blue/yellow
85 - Pink
None of the headlight relay wires (all factory) are heavy enough to carry low beam current.
Headlight and step relays check good on the bench with a 12V source and an ohmmeter.
Should the headlight relay be carrying headlight current?
Could a failed bulb failure warning device be the cause of the no-headlights problem?