Fuses and tips how to troubleshoot fuse issues on Mercedes Benz W123 W126

Yesteryear's torpedo shaped ceramic fuses are still available today. They work pretty well, but you need to know how to tell which one goes with with circuit. Here is a quick guide to W123, W126 and many other older Mercedes Benz fuses, the fuse card, and the fuse holder box.
Here is one link for ceramic fuses: www.amazon.com/HELLA-00348180...

[@RexRaven22]

Your voice is so relaxing. Trying to figure out my dad's 1980 300CD. Thanks for your video.

[@straybenzes]

:) Well, that is a true first for me that someone is commenting on my voice. Thanks and good luck with your dad's Benz.

[@ka3abneh]

Keep up the good work buddy 👍🏼

[@straybenzes]

Thanks!

[@MrGreencheetah]

Awesome video -- you know lots of good stuff!!!

[@straybenzes]

Thanks!

[@ularsach]

Great video! Saludos desde México

[@straybenzes]

Gracias!

[@grantbellinger7403]

Beautiful matey!

[@straybenzes]

Thanks!

[@allanriches9381]

Great information 😉

[@straybenzes]

Thanks. Glad you likes it.

[@saadalghamdi3203]

Good job. I like this informichion

[@straybenzes]

Thank you, Sir.

[@legereric4141]

Très bonne vidéo , et en plus vous parlez suffisamment lentement pour mon niveau d’anglais plutôt « léger »! Je comprends tout! Un partît Français qui roule en 560 sec de 1990 ( enfin quand on sera plus confinés !) Tenez bons les Américains !✌️

[@straybenzes]

Salut Eric ; Merci pour votre aimable commentaire. Je suis heureux que vous tiriez quelque chose de la vidéo. Amuse-toi bien avec ta Benz de classe S et bonne chance pour travailler dessus aussi. Veuillez accepter mes excuses pour la mauvaise traduction française. Soyez en sécurité et restez en bonne santé !

[@wernerdanler2742]

Hi Ralph! Glad to see you are still making interesting videos. I, on the other hand am an avid reader, so now have nothing to read because the libraries are closed till the end of April, maybe longer. Anyway, my Benz and Peugeot both had the lozenge type fuses. I think they were ceramic but aluminum metal and nothing really holding it together. I had to be very careful handling them. They would corrode easily so had to constantly clean them. I never found any brass or copper ones. Today I put a new door stop on my e320 and thought that would have made a good video. It is not an easy job. I just wish Mercedes engineers would simplify things like that. They should make it removable from the outside instead of having to remove the door card and wrestle it out of the door. I now have to replace the rubber grommet on my mono-wiper that seals the base of the arm to the firewall. I have watched several videos on taking the whole thing apart and disassembling it just for that. That's another one where they could have made the arm removable off a stud from the top like the regular wiper arms. These things have a very complex mechanism that makes it go up and down so it covers the entire windscreen but you have to take the whole assembly out of the car to do anything on it. Have a great week and I look forward to your next video.

[@straybenzes]

Thanks, Werner. Good luck with the "pumper" wiper. Everyone is affected by the pandemic. Stay healthy!

[@bobjohnson8206]

Mercedes source has the copper ones, hope this helps you out. They also have a video on how to clean the connections along with a special tool to remove the fuses.

[@wernerdanler2742]

@@bobjohnson8206 Thanks Bob. I remember him mentioning it. However, I no longer have either of those two older cars. Mercedes got rid of those fuses but introduced a whole new set of problems with their bloody minded engineering. Lol

[@bobjohnson8206]

@@wernerdanler2742 Sad to learn you don't have the cars. Despite their problems I still believe they build the best cars.

[@wernerdanler2742]

@@bobjohnson8206 I have the 2001 e320. I like it and it is pretty solid but stuff still keeps breaking. I replaced both back window regulators a month or so ago. They are pretty easy to do. They use cables. The right front one is bad and so I got all the rivets out but cannot break the screw loose that holds one leg of the cissor mechanism onto the track at the bottom of the window. I also just had to replace the alternator. It is a Valeo and I have been down with that for two weeks. Just got it on today. Takes constant work to keep it going and I am now 71. To old for this stuff!

[@twdarcy]

Another great video. I had no idea they were making plastic bodied fuses. Thanks again.

[@straybenzes]

Yeah, that is about as cheap as you can make a fuse. Happy wrenching!

[@dentistmgorky]

Thank you

[@straybenzes]

;)

[@parker2963]

Got my grandfathers 88 300E and was very confused when I opened the fuse box.

[@straybenzes]

It is something, right?

[@iyokeobinna2363]

Pls do a video on how to use multimeter to find fault especially when my car refuse to start

[@straybenzes]

Oh wow. There are so many reasons why an engine will not start. Some are due to mechanical issues, electrical and fuel system issues are also possible. Does the starter motor work and does it turn the engine over?

[@caryramsey1565]

Did you ever figure this out? I'm having the same issue right now. Trying to figure out how to test these fuses. The vehicle will not turn over for some reason.

[@pamed76]

Thank you. May I give you an idea? In my 126 I replaced the fuses with ceramic copper ones. No corrosion because of the difference in metals. And I replaced the auxiliary fan fuse with an external one. Never any problems after that.

[@straybenzes]

Amen! Challenge is always finding a source that still carries those type of fuses. The market is flush with th cheap plastic/aluminum ones.

[@pamed76]

@@straybenzes I’m so sorry to hear that. But I can send you some, if you want?

[@x-Topic]

Where can you find these old type of fuses?

[@straybenzes]

Hmm, did the link in the video description not work?

[@anthonyyoung8781]

❤❤❤❤❤❤❤❤❤❤❤❤ thank you

[@straybenzes]

Glad you liked it.

[@mykcarrestoration3965]

w201 turn signal works, but when driving, all of sudden it stops working, and starts working again, example: when im steering into turns it stops and again works, when steering straight? any idea where can i look for the issue? thanks buddy! and also, my hazard light only works for left signal, both sometimes works, and sometimes dont

[@straybenzes]

This could be a variety of problems. Did you change out the turn signal relay yet? The next issue could be the multi functional stalk and / or its contacting mechanism. Finally, This could also be an issue with broken wires or other connectivity issues. Good luck.

[@MAGNESIUMBURN]

Thanks for posting this helps..

[@straybenzes]

Thanks!

[@mkmk4314]

Hello,thank you so much for all you do. I do have a 1989 Mercedes Benz 300se and the fan is on running every time I drive the car. I have now removed the auxiliary fan fuse in order to keep the car quiet. Any advice from you about this issue? Please reply thank you so much.

[@straybenzes]

Yeah, there are a few circuits that tie into the aux fan. When it operates continuously is it running in low or high speed? If it is low speed check relay K10 and swap it out with K9. If it now runs in high speed then the relay is bad. It could also be the S32 refrigerant high pressure switch that may be stuck in closed position. It could also be that you have too much freon in your AC system. If it is constantly running at high speed then it could be due to a stuck relay K9. Switch out with relay K10. The engine coolant sensor B10/8 could be faulty also. Disconnect it and see if the fan stops. It sit on top of the engine in the front. Finally and unfortunately the most expensive thing to fix would be a faulty ACC automatic climate control unit. Hoping this will help you. Good luck.

[@mkmk4314]

The fan runs at a very high speed and also the air conditioning is really weak even though I turn it on high it stays the same way with little cooling and slow running. Let me try the fuses and relays you have told me about and see what happens. Please thank you so much. Moses.

[@straybenzes]

@@mkmk4314 The weak AC performance may simply be that your system pressure is low and you need to recharge and also figure out if there is a leak. The high speed fan situation may also be related to the engine coolant temp switch S25/5. It closes at 105 and 115C with the former letting the aux fan run on high speed and the latter switches the AC off temporarily. Good luck

[@mattmayo3744]

My 124’s turn signal goes on and off most of the time. What seems to be the problem? Thank you

[@straybenzes]

I assume that you are not pulling an April's Fool joke on me - blinkers go off and on :) So if I understand correctly they work intermittently. If so then you may either have a wire break or the turn signal stalk mechanism under the steering wheel is faulty. I have only come across one stalk issue so far. What model year is your 124? Early 90's ones were notorious for wire insulation failure due to that stuff having been made from more environmentally friendly materials. I would get a power probe and start tracing the respective wiring to flush out if and what circuit may be bad. You did verify that your blinker relay is not the trouble source, correct?

[@orlandocorpuz9818]

how to get windows and sunroof to oppen

[@straybenzes]

Oh my. This is a heavy hitter with many root causes. If no window is working then check the switch panel. Often they have solder joints that need to be reworked. I have found defective motors too. Finally it can also be the window regulators or the guides that need adjusting. The roof is usually the roof ides needing to be cleaned. It can also be the gear clutch needing your attention. Try using the plastic gear shaft extention tool and carefully opening the roof using a socket wrench.

[@ItsAli4]

Ralph, thank you for the video and I hope you and all your family stay safe. Unfortunately, I can NOT find ceramic fuses? It seems the only ones available are the plastic with aluminum inside. Maybe you can list where to buy in your videos? I have searched online but no luck! Thanks again for the video

[@straybenzes]

Yes, indeed. It is not easy to find them. I put this link into the video's description: www.amazon.com/HELLA-003481803-Ceramic-Fuse-Assortment/dp/B000VU7D90/ref=sr_1_10?dchild=1&keywords=ceramic+car+fuses&qid=1602938225&sr=8-10 Good luck.

[@ItsAli4]

@@straybenzes Thanks for the link but I also checked Amazon. The link you have provided is for the Aluminum ones which incidentally have been out of stock on amazon. I appreciate your help anyway. Thank you so much

[@straybenzes]

@@ItsAli4 MercedesSource.com has a few ceramic ones and also the copper alloy ones left, but that is indeed probably the end of that. Good luck!

[@DarKXeroX13]

Fuse no. 3 keeps blowing all the time. I get no interior lights. where should I look to find the shortage ? Also. in the footwell in the passenger side. there was a conector that was heavily corroded. ¿can this be the problem?, idk how to reconnect the cables. ¿how can I know which I have to connect to each one ? Its a 1986 300e w124. Thanks!

[@straybenzes]

Fuse 3 handles the parking/tail light on the right, inside illumination, the headlamp washing control elements, the warning buzzer, and the instrument cluster lights. So here go through one item at a time to see if there is an issue. I would start with the tail lights. The connector in the footwell may or may not have anything to do with it. What is the wire color and what is it connected to? Corrosion on wires can cause all sorts of other issues too.

[@DarKXeroX13]

@@straybenzes can I send you some pictures of the wires? The wires go up through the pilar passenger side I think. The wires are brown, green and yellow. Also, I had the headlamp washing pump disconnected because a I had a leak, can this be the issue? Thanks for the answer!

[@straybenzes]

@@DarKXeroX13 Here is the wiring diagram for your car. procarmanuals.com/pdf-online-mercedes-w124-etm/Page 130/3 shows the instrument panel circuit. This will help you in eliminating the parts that could be the problem and the wiring colors are mentioned on it. You may want to invest in a power probe www.amazon.com/TopDiag-Automotive-Multimeter-Oscilloscope-Motorcycle-dp-B0BZ4HR34M/dp/B0BZ4HR34M/ref=dp_ob_title_def Hoping this will help you get started.

[@josephdimas2548]

Can you show how to fix a broken fuse holder

[@straybenzes]

That is an interesting topic. How or where did yours break?

[@LiviuRo1]

Can you do a video about memory seat? We all appreciate your videos.

[@straybenzes]

Thanks! I have a few videos coming up about the AC system but I have a few videos about the memory seats in the works. Which part would you like to see me cover?

[@LiviuRo1]

@@straybenzes I dont know where to start diagnostic. The memory system is dead, it does not do anything. My car only has 60K

[@straybenzes]

@@LiviuRo1 Thanks, that helps. Is the passenger seat dead too?

[@LiviuRo1]

@@straybenzes yes, both sides

[@straybenzes]

@@LiviuRo1 Check the blue 25Amp fuses with the letters a and b. Are they OK? Check if you have power there with a multimeter.

[@hugoortiz3932]

El fisible del ventilador se calienta y se quema

[@straybenzes]

Creo que se refiere al ventilador auxiliar del radiador principal. Asegúrese de girar ese ventilador con la mano. Debe girar libremente sin hacer ningún ruido chirriante. También, por favor, compruebe la resistencia del ventilador auxiliar para el ajuste de baja velocidad. Se sienta detrás de la pared del fuego debajo del aumentador de presión del freno.

[@darcypolinsky7575]

Hallo, habe ich it was andere fragen, können Sie bitte helfen

[@straybenzes]

Ich werde es versuchen. Einfach fragen .

[@darcypolinsky7575]

@@straybenzes Danke, hab ich aber viel zu erzählen kann ich nicht alles aufschreiben müssen wir telefonieren

[@straybenzes]

@@darcypolinsky7575 Ok.

[@jndeprez4362]

VERY LITTLE COPPER GREASE

[@straybenzes]

That can indeed help. Dielectric grease does work as well.

[@johnwayne6588]

Lr

[@straybenzes]

😁