Hey guys, got my car running again after replacing the lower control arms, tie rods, brake calipers/rotors/etc. Anyway, now it's on to less critical items. My low beams work just fine. Fog lights seem to work (at least the left one does, driver's side doesn't but I'm guessing that's a bulb). However, the high beams do not work. When I pull the stick, the indicator on the dash does not come on and the high beams do not activate. The low beams turn off. When I pull back to "flash" the low beams stay on but the high beams do not activate. I checked the fuses (though I admit I could not really tell from the FSM what fuses are what, the text is too blurry for me to read). I didn't see any fuses that looked obviously bad though. I've replaced the combo switch (the one that came on my car barely worked at all, almost nothing worked) I got a used on on ebay and it seems to work fine.

What should I look for? I'm not a stranger to wiring troubleshootings, but generally I have a nice clear wiring diagram from the FSM to work with instead of a low resolution grainy garbage picture that looks like someone scanned a copy of a fax lol.

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2010 Mercedes E350 4Matic - 77k miles
1986.5 Nissan D21 V6 4x4 - 276k miles
1987 Mercedes 190D 2.5 Turbo - 3??k miles
1983 Mercedes 300SD turbo parts car
2017 Honda CBR500R - 15k miles
2016 Suzuki GSX S1000 - 9k miles

Have you confirmed that the bulbs are good?

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Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]

Seems like it would be weird for both of them to be out, but no I haven't replaced them.

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2010 Mercedes E350 4Matic - 77k miles
1986.5 Nissan D21 V6 4x4 - 276k miles
1987 Mercedes 190D 2.5 Turbo - 3??k miles
1983 Mercedes 300SD turbo parts car
2017 Honda CBR500R - 15k miles
2016 Suzuki GSX S1000 - 9k miles

You want to check your fuses more carefully, using the chart printed on the cover of the box. It's possible that both headlights are bad, but the indicator light would also be bad. Also possible that it's the switch. Finally, the bulb sockets themselves are known to fail.

Where I would start is to pull the bulb socket and check to see whether the high beam side is getting power, then go from there.

A quick check of the fuse layout for the w124 shows fuse #15 for high beam left and fuse #16 for high beam right and the dash indicator.

Attached Thumbnails

 

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Brian
87 300Dturbo 180K #14 head still running R-12 SOLD 12/2017
02 F350 Powerstroke 180K
05 Chevy Express 1 ton w/Royal Utility box 120K
08 Infiniti FX-35 40K
15 Golf Sportwagen TDI 35K
10 Sprinter 3500 chassis with a Class A Winnebago on it. 56K

He's driving a 190DT.

oops. Sometimes I assume everyone drives what I drive.

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Brian
87 300Dturbo 180K #14 head still running R-12 SOLD 12/2017
02 F350 Powerstroke 180K
05 Chevy Express 1 ton w/Royal Utility box 120K
08 Infiniti FX-35 40K
15 Golf Sportwagen TDI 35K
10 Sprinter 3500 chassis with a Class A Winnebago on it. 56K

I have them. The fit is VERY tight in the 190. They work fine, but I think they are a bit less bright than stock. They do look a lot better than yellow plastic.

You do have to change the socket to a six pin to install them, because they are set up for city lights. i don't recall the part numbers.

Just to update if anyone finds this in the future - the problem ended up being in the fuse box. The fuse was fine (which is why it tested good) but the connections that the fuse goes into had corroded or something. I used electrical contact cleaner and a Q-tip to scrub a bunch of crap off of them and it got the lights working properly. I went ahead and cleaned a bunch of the other fuse holders as well.

__________________
2010 Mercedes E350 4Matic - 77k miles
1986.5 Nissan D21 V6 4x4 - 276k miles
1987 Mercedes 190D 2.5 Turbo - 3??k miles
1983 Mercedes 300SD turbo parts car
2017 Honda CBR500R - 15k miles
2016 Suzuki GSX S1000 - 9k miles