Been planning to put a new bulb in that lower passenger side foglight for a long time now. After work I finally bought the halogen light from autozone figuring a blown bulb was the issue all along. I also picked up another fog light bulb for the drivers fog light inside the headlight housing (upper fog) which was also out.

Long story short, both of the new bulbs made no difference. Ohh boy do I hate electrical gremlins! Fuses were fine, time to whip out the multimeter and see whats going on.
I start troubleshooting the lower fog in the bumper. Multimeter displayed NO voltage at the socket. Some previous research brought forth the issue of a worn foglight harness, in which they cause intermittent problems from corroded or broken wires ect. This wire/harness consists of one end of the wires epoxied into the cap that is screwed into the foglight housing to keep moisture, water, and crap ect. out. The other end is a plug type connector. I removed the harness for inspection. It was pretty obvious that this epoxy/sealant hardly did its job. How do I get this epoxy crap out? About 10min in the oven at 250 degrees Fahrenheit leaves this stuff with a play-doh like consistency which in turn makes it easy to peel out. As you can see in the photos, this is the step the photos start at. The epoxy has been scraped and peeled out revealing two BADLY corroded male/female blade connectors. The female connectors can then be easily removed so the male connectors can be cleaned with a wire brush. In this case you will need two female blade type connectors to replace the corroded ones. These can be bought at most automotive stores, bought mine at a local fea-market. I soldered the new connectors on the original harness (harness is now only about 1 inch shorter than original). If length is an issue, creating a longer harness is about as difficult as buying wire, cutting two pieces the same length and soldering them onto the connectors, I'd recommend wrapping them with electrical tape afterward. Now you have a revamped cover end for your harness, but how to seal it? I used fiberglass epoxy resin, just poured it in and let it set. Its rock hard and completely sealed, I just added a small bead of silicone around the exit where the wire pokes out of the resin to assure a tight seal. Test for continuity with a multimeter to assure there are no open contacts.

Ironically, non of this was my issue. Apparently both fogs are activated by a relay that allows only either or to be on simultaneously. This relay is located behind the headlight housings and was the sole cause of my lighting issues. They are industry standard 5 blade/pin automotive relays that can be bought on ebay for a few dollars a piece.

 

Good work. I would have covered the electrical connections with vaseline to prevent moisture and corrosion.

 

Ahh! Your right! Well lets hope its sealed good enough...dielectric grease is a must for this DIY.

 

Looks OEM great job!

 

Very nicely done.

 

UPDATE: The new Chinese 2 dolla' 5 prong relays came in. Thier still blinding slow fastlane drivers 2 weeks later even if they last me a year it's two buck a pop rather than $19 each at the dealer. TRAIN-HORN TIME!!!!!

 

Time to do mine for sure.

Will also rip out the inner main housing light harness as my left one is out. New bulbs everywhere.

 

Nice, I had a problem with mine but turned out to be a broken wire inside the harness where the clip holds it on to the bumper frame.

Let me see if mine operates correctly:
first pull turns on the headlamp unit foglights only
2nd pull turns those off and turns on the bumper foglights, but also turns on the rear foglight...

cant have both sets on at once, is that right? i'd rather have everything on, for spotting deer and other unfortunate rodents to wander into the street on the backroads at night.

 

I'm not quite sure what you are saying but my lights work like this:

1st turn = parking/marker lights
2nd turn = parking/marker lights + headlights
1st pull = fog lights
2nd pull = fog lights + rear fogs
If I push my turn signal forward it turns on my brights (yellow lights in headlight)

 

Funny, I immediatley thought to myself the same exact thing! It would be a great advantage to have apron fogs, headlight fogs, and headlights all on at once. I will probe around the wiring diagram and see if there might be a easy mod using an extra relay to have all on at once with highbeams or something like that. It would be incredibly beneficial to people living in rural areas with no streetlights. As for the operation of your lights, seems to be the same as mine .

503C43 ////AMG, that sounds normal to me. Only difference is that I swapped my yelow fog bulbs for cear white 55W ones (I think 55w?).


I'll look into the "power fog mod" to see if it could be a easy and safe DIY with a simple relay and some crimp splices so you can easily revert back to stock at any time. Thinking about having the second pull work like stock with the addition of the apron fogs so you are really lit up at night if you need to be. Sound good?

 

I guess I don't understand what headlight fogs are, are you referring to the yellow brights? Are you guys saying you can't have headlights, brights, and apron fogs on at the same time????

 

Headlight fogs are the inner lights that illuminate in your headlight housing (the yellow ones, yup). The high/low beam is one bulb, you can have only either or on, its the outer light in the housing. I don't seem to be able to get my headlights (high or low), foglights, and Apron fogs to illuminate all at once. It is either headlights and fogs, or headlights and apron fogs. It this strange? My manual seems to concur.

 

Do you have HID headlights?

 

lets get this straight:

Headlights = High(brights) & Low
Apron fogs = fog lights in the front of the car in the bumper
fog lights = rear fogs lights????

I just went out to my car and turned on everything at the same time so I am unsure of what you mean. I turned on my brights, my head lights, my fog lights (front bumper) and my rear fog lights. I do not have my fog lights installed on the front bumper as I am awaiting the delivery of my crystal fogs but I had the switch all the way out and everything was on. Perhaps the addition of my fog lights will trigger a relay or something that will turn off my lights??

 

The headlight housing itself has two bulbs. One for the headlight high and low beams (ONE BULB). One for fogs (yellow on stock setup, I put a clear bulb in mine).

Headlights = One bulb (for high and low beam depending on stalk position)


regular fog lights = rear fogs & front fogs (your yellow lights in the headlight housing)

Apron fogs = also known as bumper fogs ect. are the ones mounted in the AMG front spoiler.



That make any sense? I cannot have all three on at the same time, only headlight and either bumper fog or regular fog lights.

 

how do I turn those on?

 

Turn knob to right for parking lights or headlights then pull out one click. Second click turns off regular fogs and turns on rear fogs and front apron fogs.

 

hmmmmmmmmmm.....
when I turn my knob 1 click it turns on my parking lights and 2nd click turns on parking lights + headlights, when I pull my knob out 1 click it turns on my fog lights (apron lights) when I pull out my knob 2nd click it turns on my fog lights(apron fogs) + rear fog lights, to turn on my brights (yellow bulbs in head lights) I pushed my turn signal forward........ I can have all of them on at the same time

 

Whoa....that explains the confusion! Something is very wrong, those yellow lights are supposed to be the fogs. The yellow light wavelength does not reflect light back to the driver blinding them when driving in weather where water particles are suspended in the air (fog). Pushing the turn signal stalk should activate the high beams NOT the fogs. The high beams are basically low beams with an additional filament being powered at the same time in the same bulb to produce more light. It seems as if your high beams (brights) have actually been eliminated or rewired to the reg. fogs?



Just to straighten things out:
Once click to the right = parking lights on

Two clicks to right = Parking light + Headlight on(turn signal stalk pressed forward at this point should activate brights)

One click outwards = Parking lights and Headlights still on. Regular headlight fogs now activated(yellow fogs located in headlight housing)(turn signal stalk pressed forward should still activate brights)

Two click outwards = Parking lights and Headlights still on. Regular headlight fogs now turn off(yellow fogs located in headlight housing)(turn signal stalk pressed forward should still activate brights) Apron fogs and rear fogs activated




I wonder if someone with a C43 can chime in here. I'm pretty sure there is something wrong on your end though as my W124 has the same exact setup. (Minus the apron fogs) But it has high beam and low beam along with yellow fogs in the headlamp housing that are activated on the first knob pull out.

 

Lol... I had to refer to my manual that CAME with the car to figure out how to work them . I'm sure that mine work as they should

 

First click out should not activate apron fogs. Stalk should have nothing to do with the yellow fog in the headlamp. I'd double check, here are both W202 manuals produced. Can't get more thorough than that.

 

This is only confirming the definitions I have been using. "parking lamps plus low beam or high beam headlamps (combination switch pushed forward) ; 1.) "high beam headlamps" = yellow lights next to the low beam in the head light 2.) "combination switch" = "stalk" 3.) first pull = "front fog lights in apron" 4.)2nd pull = "rear fogs"

You keep talking about a fog in the head lamp where is the switch for that???

 

high beam headlamps are not the yellow lights next to the low beam in the head light

Yellow lights next to the low beam in the headlight are the foglights not headlights or high beam headlamps. The low beam light is ALSO the high beam, they are the same bulb.

The fog in the headlamp SHOULD go on when you pull the knob out first click.

"Front fog lamps (pull out one stop)"

 

how do you turn on your apron fogs?

 

Apron fogs SHOULD go on with the rear fogs thus it would be on the second click out. We'll get this figured out .