3. Left Headlight Does Not Light Up, Bulb Is OK

CIRCUIT OPERATION
The low-beam side headlight relay supplies current to the left headlight through dedicated fuse number 12, and the high-beam side headlight relay supplies current to the left headlight through dedicated fuse number 7.

TECHNICAL DESCRIPTION (COMMENT)
If only the right headlight does not light up, there may be a fault in the harness and connector from the dedicated fuse to the left headlight.

TROUBLESHOOTING HINTS
- Damaged harness wires or connectors
- Blowout of the dedicated fuse

DIAGNOSIS
Required Special Tool:
MB991223: Harness Set




STEP 1. Check the headlight (LH) power source
1. Remove the headlight (LH)
2. Measure at the harness side of headlight (LH) connector A-27.
3. Measure voltage between terminal number 1 and the ground at the column switch LO position.
4. Measure voltage between terminal number 3 and the ground at the column switch HI position.
- The voltage should be approximately 12 volts (battery positive voltage)
If approximately 12 volts, go to Step 2.
If not approximately 12 volts, go to Step 3.




STEP 2. Check the harness wires between headlight (LH) connector A-27 and the body ground.
If the harness wires between headlight (LH) connector A-27 and the body ground are damaged, repair them. Check that the malfunction is eliminated.




STEP 3. Check headlight (LH) connector A-27 for damage.
If headlight (LH) connector A-27 is damaged, repair or replace
it. Refer to Harness Connector Inspection. If headlight (LH) connector A-27 is in good condition, go to Step 4.




STEP 4. Check the harness wires between headlight (LH) connector A-27 and dedicated fuses number 12 and number 17.
If the harness wires between headlight (LH) connector A-27 and dedicated fuses number 12 and number 17 are damaged, repair them. Go to Step 5.

Step 5. Check symptoms.
Confirm that the headlight (LH) is illuminated.