Mercedes 300D W123 Instrument Cluster Gremlins & Grounding Issues

Fed up with wacky, fluctuating fuel and temperature gauges in my Mercedes 300D, I hunt for the cause of bad grounding in the gauge cluster as well as the connector that plugs into the back of it.

[@sophiathe380sl]

Thanks for the video. I have a similar issue with my 380sl. Everyone says it’s a grounding issue but nobody says what that actually means.

[@christopherk5021]

Me too. Same problem but many different solutions

[@MrVintagemoto]

I just recently bought a W123 280CE with all small gremlins possible and I am preparing myself to deal with them. Thank you for a nice informative video!

[@jimh3362]

Thanks for this video. This is exactly what I found on mine. Did the same repair. What a life saver!!

[@backyardcreator2170]

Thank you for this! I pulled my gauges out and found the solder joints on that ground tab you soldered the wire to was broke . Re soldered it and now I'm at .3 ohms. About to put back together now.

[@georgecurtis6463]

To solder those burnt circuit ribbons it's best to lay a few wire strands across the gap. These jumping gauges normally require just loosening and then tightening the gauges themselves. Good video.

[@KristianBurford]

Great video, good to know about this failure point. btw, if engine is taking too long to get up to temp the thermostat may have failed open (chassis failure) which slows the warm up period increasing wear--this happened to me and it took a long time to catch it as temperatures were never excessive.

[@volkansorkun]

great advises and explanatory video, i have w124, also that is doing the same thing, will check grounding right after this. thanks for your effort to explain.

[@DHRN-rq1qq]

Really great video thx for all the explanation

[@qinglingliu6940]

Thank you for sharing

[@coachgym]

Great job, John.

[@allanriches9381]

Thanks for the video, something to put in the memory bank for future use.

[@Audiopel5269]

It happens to me the same the same way I fix it the way you did and it works good

[@ImpalamansGarage]

Excellent repair!

[@thedillestpickle]

I've got one even worse. If I use the turn signals, sometimes no issue, but by about the tenth time I turn, suddenly all my dials go to zero other than speed and oil pressure. I also lose my signals, and nothing comes back until I let the car sit for some time and start it up again.

[@kuldipdhak7972]

Thanks is helpful video

[@jonathan2870]

My man. I had the same problem, thanks.

[@brittanywright9646]

Thank you. Having a similar issue as well, except my entire driver's side is dead.

[@eternalbeing3339]

Same. My driver and passenger window switch does not work. Left turn signal is solid, buzzes with the lights on.

[@brittanywright9646]

@@eternalbeing3339 So I found the problem, which was interesting: both the fuel level and oil pressure gauge failed simultaneously. I ordered 2 new ones and everything is fine now. One thing that I did notice that happened around the same time was that the charge indicator light would be on like the alternator (or VR) was failing and also my ABS computer (behind the battery) failed. When I tested the alternator I was getting an output of like 12.x volts until I gassed it a bit and then I would get 14 - 16 volts, so I replaced the VR. I think maybe the increase in voltage could've damaged the gauges. Unfortunately, I don't think the OVP protected the components because I believe the threshold of increased voltage starts at around 22 volts. So I also had to replace the ABS unit.

[@pichulon703]

Thank you so much my temp gauge doesn’t even move 🥹

[@saadalghamdi3203]

Thanks its help for my w126

[@tttboyy]

Great job!

[@greggschuder7478]

Thanks!

[@robertorochamartinsrocha7041]

Very nice video... 👍👍👍👍👍👍

[@qwertymommyt]

THENKS. YOU HELP ME

[@vintage76vipergreenBeetle]

Nice job.👍

[@junaidibrahim1133]

Thanks

[@leonardoreboredo3569]

The Best. Gracias.

[@bberroutberrout1043]

Good man

[@alpaslanilkman3122]

Thank you so much.

[@CrToloss]

Great job..

[@HobbyMercantile]

That is exactly the same thing that my car is doing!!

[@edi6522]

30 min ride to get up to 80 degrees is way too long, please check and change the thermostat as it may be stuck open.

[@waseemsalem6086]

good video

[@eternalbeing3339]

Having similar issues with my 82 300sd. Cannot figure it out. When my lights are on the left turn signal buzzes and stays solid. Swapped the cluster with another one from ebay, same problem.

[@kendog1995]

Hey did u ever figure out the problem?

[@brianmilligan1787]

It's not the w124 is an old car and the fuses corrode you have to change them all corrosion it is not a problem with gauges I had that problem and all working by changing all fuses under bonnet £3.45p

[@leodagne1517]

Very informative video! Im having a similar issue however it’s regarding my temperature gauge. The car is running at 85c at the gauge however the infrared thermometer is showing it’s 65c. Am I having a ground issue as well? I changed the engine coolant temperature sensor. I own a 85 300d turbo. Thank you

[@shawnmah1604]

Hii, I have a w123 and my tachometer is fluctuating when I switch on head light and turn signal. Had already fried up 2 alternator. Is bad grounding the culprit?

[@kuldipdhak7972]

My car have same problem 1985 w 123

[@levcohen1347]

👍👍

[@sanchez3152]

where can i find the pin diagram for my 1994 s500 ? help please

[@judgesmails855]

Any luck? I'm trying to find the 15 pin diagram for my 84 380SL. Please let me know if you were able to find one for you vehicle.

[@waseemsalem6086]

brother l have Mercedes Benz 123