convicted

Hello,

My bulb is good, but the FL (low beam) HID is not working. Is there a fuse for it, or should I assume the ignitor box needs replacing?

Edit: After more research, I should include that the FL "peanut light" (DRL) stopped working prior to losing the low beam. Does this indicate a bad ballast/ignitor?

Thanks in advance.

Serndipity

The left Xenon low beam headlamp is fused at position 8 in the N7-1 Illumination Control Module.

convicted

Is that the front fuse box, or the rear? Pardon my ignorance.

Serndipity

Above picture shows the location of N7-1 of your Illumination Control Module.



The above picture shows the location of the fuses in the N7-1 in your Illumination Control Module.

The fuse for all of the left side standing lamps, which includes the peanut light that you referred to, is located at position 10.

If your left Xenon low beam headlamp fuse (in position 8) is not blown, I'll provide additional troubleshooting information to pin down, either faulty wiring or a Xenon headlamp control module.

convicted

Thank you so very much! I will check this today (I completely forgot about that location).

EDIT: All of the fuses are good. I noticed yesterday that the "peanut lights" (DRLs) burned the wires (in half) on both sides when I replaced them. Is that a SAM issue, ground issue, Ballast/Ignitor issue?

Thanks again!

Serndipity

The headlamp's harness wire size, that powers the standing lamps,(e.g. peanut, tail and side markers) is only 18 AWG, which has a maximum current load capacity rating of 5 amps.

The reason that the wire burned in half, would be that it came in contact with a high amperage wire, exceeded its current carrying capacity and burnt out like a fuse.

After finding that the F8 fuse is not blown, here are the 2 tests that a Mercedes trained tech would perform.




Test 1.0 verifies the voltage at the N7-1 module, which should be capable of supplying power to the left low beam Xenon headlamp assembly. If that test fails, the fault is likely within the N7-1 module wiring.

Test 1.1 verifies that the voltage and amperage currently being supplied to the Xenon control module. If it's less than 35 watts or more the 45 watts , the culprit is likely the Xenon headlamp control or ignition modules.

Important: when the headlamp is initially turned on, the current flow will be very high, so to avoid destroying your multimeter and/or a bad outcome, you'll need 2 multimeters and an inductive pickup to conduct this test. The required connections are shown below.

However, the test can be accomplished safely without an inductive pickup and a single multimeter, by a shade tree mechanic, proficient with several other alternative multimeter techniques that deal with the initial high current surge.



FYI, after 30 seconds, 40 watts of power at 12.6 volts, the nominal current flow should be a tad over 3 amperes.