Off and on (for a few years) the right front parking light will not work. After 1-6 weeks it works again; then it's off again for a period of perhaps 3 days to 2 months. The turn signal light always works. Sometimes if I pound on the light lens, it comes back on; thus I don't think that it is the headlight switch. So, does anyone know where the ground wire for the parking light is? AND, does anyone have any suggestions as to what to check? I switched the bulb with the left side, and switched the ceramic socket adapter (?) with the the left side and still the same problem, while the left side always works. Going over bumps doesn't help. So.....help!

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Paul 1987 300 SDL; 2000 ML; '69 MGB; '68 VW Fastback

It must be something internal to the light assembly, such as corrosion of the socket. The RH turn signal and Parking light both ground at G101 on the radiator support.

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Sam

84 300SD 350K+ miles ( Blue Belle )

It could be the light monitoring relay inside the fuse box. It is the longest relay, about 1" x 6". It's function is to monitor the lights and gives a warning light on the dash if one of the bulb is busted. Try re-seat the relay first or get a replacement from the JY. There are plenty of junk W126 cars.

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Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

Yes,when the parking light is out, the dash light comes on. Will check the relay as you suggested. Thanks.

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Paul 1987 300 SDL; 2000 ML; '69 MGB; '68 VW Fastback

Bump.....

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Paul 1987 300 SDL; 2000 ML; '69 MGB; '68 VW Fastback

Interesting I have this exact same problem on my 124, same light and everything.

I suspect the monitoring relay has an intermittent connection inside based on earlier troubleshooting attempts.

If I get some time this weekend I will dig into it and post back.

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The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech

Pushed the relay around to make sure the contacts were clean. Now I'll have to wait a few months to see if the light goes out! Let me know what you find. Thanks.

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Paul 1987 300 SDL; 2000 ML; '69 MGB; '68 VW Fastback

Any other ideas out there?

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Paul 1987 300 SDL; 2000 ML; '69 MGB; '68 VW Fastback

It ended up being a bad connection inside the monitoring relay.

The pin X3:7 had a loose riveted connection to the brass strap that ends up soldered to the board. I was able to heat up the rivet and strap and apply some solder to the rivet head and strap.

This pin feeds "right parking light" voltage to the right front parking light bulb.

__________________
The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech

Thanks, I'll try that. The people on this forum have been great through the years offering super, money saving info. This forum is the reason that I can tell people that the SDL has been the cheapest car to keep on the road of all the cars that I've owned.

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Paul 1987 300 SDL; 2000 ML; '69 MGB; '68 VW Fastback

So pounding on the lens was just a coincidence repair? Corrosion of the socket is the most typical problem I've seen on various cars. It might be more than one problem causing the symptom.

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Sam

84 300SD 350K+ miles ( Blue Belle )

jay bob: I must have a different relay from you. Mine has 2 opposing (1 inch apart) circuit boards perpendicular to the rivet(pins) so that i can see most of the pin-brass strap connections , but I can't get to them. Also my pins are numbered 1 to 8, 1to 16,and 1 to 10. Any thoughts and can you give me the pin number again? Thanks

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Paul 1987 300 SDL; 2000 ML; '69 MGB; '68 VW Fastback

Yes that is the right relay.

Part number 126 542 01 32 is what is in my car and is probably what you have too.

There are 3 banks of pins:

X1 is the 16 pin group
X2 is the 10 pin group
X3 is the 8 pin group

X3 pin 7 is the output for the right front parking light. Fortunately it is right in the corner where you can get to it with the soldering iron, without having to disassemble the relay.

Be careful, that pin gets HOT after you solder it (don't ask how I found that out). Also be careful not to overheat the pin or you will cause the housing to melt.

__________________
The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech

OK, I'll give it a try.

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Paul 1987 300 SDL; 2000 ML; '69 MGB; '68 VW Fastback

SD Blue: The pounding on the lens doesn't seem to help any more. I didn't record when I changed the bulb and the adapter, so maybe that did help.

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Paul 1987 300 SDL; 2000 ML; '69 MGB; '68 VW Fastback