The wiring on my Mercedes 220CE is trash

[@malcolmcowan9554]

Take each fuse out till the ignition lights go off once you do that lights go off check the fuse number. Then go on the Haynes manual. check the wiring diagram from that fuse it will give you idea were the grounds are components link to that fuse

[@colinthomas1540]

Nino, I wish you wouldn’t beat yourself up do much! You’re doing something totally different on KZbin & it’s great. Average Joe LEARNING along the way instead of professing to be the font of all knowledge!! Your video’s are great and I really enjoy them. I’m sure in time they will make you some cash but of course the day job has to take priority. Thanks for sticking with them & my vote is the ignition circuit 😜. That said, I’m not a mechanic & haven’t got a clue 🤣👍🏻

[@shaunreppion87]

That Chinese relay is the only thing you have changed, by process of elimination I’d try the original relay to see if things normalise. It’s that old saying unfortunately you buy cheap you buy twice. Although that relay is new it doesn’t mean it’s working correct

[@chrismaguire719]

The alarm is after market scorpion . Merc used them through the 90’s. I’d start off by unplugging the ignition switch and see if the dash lights go out. Have a look under the dash to see if they have stripped the old alarm out. Some of the alarms interrupted the ignition circuit.

[@AnthonyAshcroft]

I’d start by looking at ground connections. The dim dash lights make me think it’s trying to earth via other devices. Get hold of the wiring diagram and get digging and cleaning. Easpecially look at earths that are in use with the ignition key off. I’d certainly start looking at a new look just in case though.

[@redriver15262]

I purchased a GLK that had random sporadic problems, it would drive fine then turn off then I jump start it and it would be ok for several days then it wouldn't start. I thought it was crap, then during lockdown I went through the FUSE BOXES and found out that the previous owner had swapped out the fuses and relays and put random ones in that were the wrong number and even used PAPER CLIPS instead of fuses to bridge the connection. needless to say, I looked up the fuse diagrams online and put the correct fuses in, it works fine now! it was such a simple fix but I was ready to sell it for scrap, similar to ur friend with this car lol

[@neilphilip2320]

I really enjoyed this! You are in deep but in my view it's worth persevering because I adore my W124 - it's just about the only car I really enjoy driving - in anything else I prefer to be a passenger. I learned a lot from a non-starting issue - and some really perplexing idling issues. There's a fairly big and complex relay behind the battery that controls the fuel pump. I got it home by hot wiring it using copper cable and once on the bench I took a powerful magnifying glass and saw a series of small cracks in the solder connecting the output pins. So I got my soldering iron out and sucked all of the old solder out of the joints and using lots of flux I resoldered all the joints. It fixed all of the problems - and it was a guy on KZbin that pointed the way (though I forget who) to this issue. Depending on ambient temperature the cracked joints made poor contact and hence all the running issues. I had replaced the throttle cable which made no difference whatsoever. So I wish you well in this and keep us informed of progress. All the best!

[@josephjohnstone7667]

Those grounds look crunchy! I wouldn't be surprised if they are the cause of some of the issues. I'm not sure if there is a common ground for the ignition but I'll keep my fingers crossed for an easy fix 🤞

[@broomad]

I would start by getting a wiring diagram - then clean and test all the powers, grounds and any connectors. To do that you need to invest in a power probe - there are loads of KZbin videos showing how to use them - basically, it will allow you to simply touch a wire and identify if there is power or a ground present. In addition, a good test light is a life saver as it allows you to load test a power or ground. Sometimes what appears to be a good power or ground will be poor quality and fail when a load is put on it. Once you know if all the powers and grounds are good - you can focus your attention on testing specific components

[@NotEconomicallyViable]

Excuse the noob question, but is a power probe and a test light the same thing?

[@broomad]

@@NotEconomicallyViable ​ @Nino Rosella No problem 🙂 - a power probe let's you identify grounds and powers by simply touching a wire via an audible tone and/or light. If you used a test light, you would have to connect it to the positive and negative sides of the battery in turn and then touch the other end to the wire being tested to work out if it was a power or ground. Plus, the probe has its own separate ground so you can power up components independently of the car (to test if they work). Like you did with that relay. Also, some can act as a multi-meter, so you can measure voltage etc

[@paulmoores6217]

Mate, I love your videos! I love your presentation style! I love that I can learn with you! Totally get the pressure you must be under. The important thing is to look after you and your family. Being self employed is an absolute challenge in ways most folks don't get. (January would often have me in tears!...I'm sure you will get why...) Look after you and yours first! I'm sure I speak for a lot of chaps on here when I say that. We will all be here waiting when you are ready to put a video out... Don't put yourself under any pressure from us folks we are a patient bunch! Sending love to you, the missus and the little one... You do what's important to you. 😊😊🤗🤗

[@GoWstingray]

Great to see you back Nino, and thanks for keeping going!

[@ninjabearhug]

With faults like this I tend to pick one thing that's wrong - fuel gauge active for instance - then find a wiring diagram for that system and start from one end and trace your power and grounds through. If you find a short in the system then try break it down, most sections will have a few connectors where you can shorten the issue down. Once you find the issue (presumably a dodgy ground or a split cable looking at this), you'll likely fix a few of the other issues you're having. Take your time and don't just fire parts at it, you'll end up spending money you don't need to spend and get frustrated to boot! Just subbed BTW, enjoying watching you learn :)

[@GG90.]

If i am not mistaken, the only thing that goes bad in the relay is the solder joints. Mercedes had a problem at some point with the solder that was used for various electrical components. I am currently restoring a 87 500SEC and I have found cracked solder joints in the OVP, the gauge cluster, the ambient temp display etc. I would choose a resoldered MB original OVP over the cheap knockoffs. A lot of them don't work straight out the box.

[@NotEconomicallyViable]

Ahh interesting. What about if I go and buy a new OVP directly from Mercedes? Would that be as good as a re-soldered original?

[@GG90.]

@@NotEconomicallyViable That would be the ideal case, but they are a few hunderd Euros. Google for "OVP repair", there is nothing inside, really. Just a coil and a primitive circuit board with components that can be easily tested. There are no microprocessors or anything. Drop by your local junkyard and I bet you can get one for next to nothing.

[@Badger66]

Nice to see you back.... there are reason's you don't see many auto electricians it can be a nightmare fault finding. I'd put the old relay back and start taking off all bolts and terminals you can find, cleaning them up so you know that the earthing element is covered. My gut says you have an exposed wire somewhere that is causing the short, but where is the problem.

[@gezdipz5425]

First thing I would look at is throttle body shouldn't be buzzing could be short to ground there,need a diag tool. Your doing what I want to do lol,keep it up 👌

[@Involvod]

I did the same thing, absolutely blasted what savings I had to spend months making videos and try to build up the channel, I've reached the same point as you where I need to get real and actually make money again as YT doesn't even cover the cost of making a video! But it's all worth it eh 😅

[@MiracleMitch]

Your vocation is the most important. Some KZbinrs only post once a week, some even once a month. You should tackle the Mercedes wiring only when you have time to do so. It will be a slow learning process but that knowledge well worth it in the end. I will probably get that book as I have only replaced looms previously and have not had to troubleshoot the exact electrical issues per se. This is interesting stuff and pertinent to a lot of 80s and 90s car fans.

[@whitemonkey7932]

This will need an engine bay loom

[@e.j.s.1357]

We had some trouble with ignition switches on these & 201 models. These are not what they seem. There is the tumbler and lock cover, which is where you put in the key. Behind this is the steering lock assembly. Fastened to the back of this is the electrical portion of the ignition switch. All of these are separate items that can be bought, except for the lock cylinder, which you must get from Mercedes. These are ordered by chassis number, and fit the original key. You will need to prove you own the car to order locks or keys, for theft reasons. If the key seems to turn hard, or only works when inserted in a certain way, I would replace the entire assembly. The key needs to be turned to the first position(between off & run, in order to remove the plug from the electrical portion of the ignition switch, and to remove the lock cylinder. If it jams, you are in for a vexatious day of work under the dash.

[@pauledwards7553]

Great video. The state of that wiring is scary. If it was a short then you would be blowing a fuse on the shorted circuit. As others have mentioned this appears to be a ground issue. First, clean all grounds you can see. There will be some on the engine and gearbox and probably on both door pillars for the interior. Good luck - I think you are going to need it.

[@broomad]

Thanks

[@NotEconomicallyViable]

Thank you so much. Made my day 🙌🏻 🙏🏻

[@M.R.C.]

Great video. I would be looking at that ignition switch first, those lights shouldn’t be on with the key out.

[@BigCol78]

Unfortunately I can't offer any help regarding your issue other than to keep up the great work and videos. I'm glad you've been able to post a quick update about Tina it would also be nice to know if you found a home for Bob? Good luck finding a solution, I'm really looking forward to the next installment 👍🏼

[@ThorMotorWerks]

Good to see another upload - You can always try putting the original OVP back in and getting the mrs to turn it over while you are tapping it to see if it tries to start - That is normally a sign that its the OVP is the problem. Not 100% convinced a Chinesium relay would be helping you - It could be fine but its worth a shot. Alot of older wiring looms start breaking down like that.

[@danieleaton1399]

Good to see an update on the Merc I would check out number 27 on here he is doing same version and got some help from a lady that breaks and repairs these and is very knowledgeable so could be worth a shot

[@davidsjenkins281]

Great video you need to go through car wiring diagram from top to bottom I would start behind the Dash and check all of the ignition wiring for any brake. Behind the Dash frist keep up with the good work 😄👍

[@1974benzw115]

Awesome job well done for Tina!!

[@johncallaghan4616]

Welcome back Nino, and another great update - don’t put yourself down so much……if everything on the cars worked perfectly you’d be out of a hobby, and KZbin would be a worse place for that! As for the Merc, the fact that she’s going live without the key is suggestive of a regularly intermittent bad earth, so you’ll have to do what many have suggested and get those wiring diagrams out, and try as much as you can to sand off all that oxidisation on those terminal bolts (I would also tape up those exposed wires, as they could be arcing to the shell or other components) It could also be that there’s an issue with the earth on the ignition switch (behind the key barrel, usually held on with a circlip or similar) The copper contact bar, which is normally engaged into the live or isolated position when you turn the key can fur up over time, so again, a scrap of sandpaper would scuff the gunk off (could also be as simple as a loose wire or a missing circlip). Lastly, (which you might think to do first) would be to systematically pull the fuses one-by-one, to isolate the ‘live, even though off’ issue - even though you’re going to have to clean up all their terminals/earth’s etc. anyway, this would help you to home in on the circuit causing the issue, so you could more directly focus on that, and at least get her started! Keep ‘em comin’ (in your own time!), hope this helps, and best of luck - oh, and Bye Bye Tina! JCHK

[@PaulRansonArt]

Like many others commenting I think a new loom is the only way to go. Given that Mercedes fitted self destructive wiring you'll be chasing faults for ever more and if it catches fire you'll be heart broken. 😃😃

[@FatBoyHog]

Nino if it’s any consolation I have the same car even down to the same colour. I have stripped it and have it close to paint now, however I found that under the headlamps was severely rotten so some welding needed. Any way good luck and keep them videos coming pal.

[@AmaanKhan-te8ll]

Some wiring schematic will help you understand how the circuit works and help you test certain points/connectors. Always start with the fuse to see if it's blown , check power side of circuit ,check voltage across the comsumer and check grond side . Learn testing methods like voltage drop testing and checking continuety There is so much to learn when it comes to electrical diagnosis ,this is only a brief guide , good luck 👍

[@moodyk1979]

Hey Nino, keep up the good work buddy, ok start with this, take out the Chinese relay and see if the dash lights disappear, then if it does, add the original relay back and see if you get the same problem or it’s back to normal again. Next, you have many ground points in that car, you pointed them out in the video, where there’s a bunch which are bolted to the bull head or near the battery and there was some near the wings I think that looked really rusty and corroded. Take out the battery and unbolt all these earths, and clean them all up with a dremel. Sandpaper or something that can really clean them up. Clean the earth wiring tags and also clean up where they make contact to the body so it’s a clean piece of shiny metal, and the bolt head too. Start there as it used to be notorious on the old cars even with Fords etc. start there and I’m sure it will help with a lot of the issues to start with 🙏🏼

[@bobbyrayofthefamilysmith24]

I h8 cops

[@dylanlawson3932]

Has it got fuel in it? Mine showed full but the gauge was faulty. It showed full all the time then it would drop for a second to show the true level, I ran it dry before I worked out what was happening.

[@paultaylor9652]

Lovely Jubbly video. It really needs asessing to see if it safe to be on the road, parking it in the enclosed space definitely needs the battery disconnected if you're going to keep it.

[@geezerdiamond]

I'd be swapping back out that new main relay - if that's internally shorted then you'll have voltage going all over the show, including back to the dashboard. It's the only thing you've changed. Does it go mental still with the old one back in?

[@mikenewman137]

My friend has a mid 90s Ford scorpio and the loom on it has the issue of the insulation coming off the wires, apparently the wiring was made bio degradable which is happening. i suspect you have multiable wires where the insulation is coming off and the wires are joining themselves together.

[@francishagen8508]

Start with the ignition switch, then do the earth points..

[@Parknest]

There shouldn't be all those dashboard lights on with the key out. It is behaving as if the ignition is switched on. That's why you can hear things running. It looks like the igntion switch has been bypassed. You need to find out where this has happened. For this you will need a wiring diagram. Forget about relays until the fundamental problem has been resolved. The first port of call should be the ignition switch which should be located behind the ignition barrel.

[@NotEconomicallyViable]

Nice one. I’ll have to dig out the wiring diagrams and I’ll get behind the ignition barrel and check the switch 👍🏻

[@kennethcroll6972]

@@NotEconomicallyViable and try unplugging it too

[@georgegonzalez2476]

The relay noise is a symptom, it’s not a problem. That era of Mercedes had biodegradable wiring harnesses. They were supposed to degrade after like 30 years, but in reality started degrading after ten years. Mercedes should have replaced all the wiring but that would cost them over a billion dollars, so no. New harnesses cost from $300 for a Chinesium one to $800 for a good one.

[@dougfields5798]

Have you checked the alternator output?.I reckon you are going to be brilliant at soldering wires before much longer .The first piece of advice I would offer you is get a wiring diagram for the vehicle,the second piece of advice is make a note of exactly what the faults are and look on the wiring diagram for a common connection ie permanent live ,switched live or ground ect and also make yourself a couple of test lights with a headlight and aside light bulb .I’m probably wrong I normally am ,good luck .

[@kennethcroll6972]

to check the alternator the car would need to be running and a volt meter on the battery to see the volt output should be around 13v's ?

[@dougfields5798]

@@kennethcroll6972 he’s had that car running more the once .Charging the voltage should be about 14.4 volts .

[@kennethcroll6972]

@@dougfields5798 thank you, i should have put a + not ?, if it go's higher than that could be the volt regulator would you say?

[@dougfields5798]

@@kennethcroll6972 Definitely, it would be nice to know the charge rate ,If it is much above 14.4 volts he may be able to change just the diode pack in the alternator.

[@carolotsful]

Was that originally from Wimbledon/Putney ? Someone I knew years ago bought one identical to that for his wife, they had a messy split and it sat in his garage for about 2 years.I remember looking at it and the battery had corrosion all over it 😳 back in 90s

[@andrewnewton5893]

That ground need sorting that will cause no end of issues as it's an engine 1

[@jpdabinett3595]

Check ALL grounds.

[@MyJon64]

That's where i usually start also

[@peterfox6256]

Think I would unplug the ignition switch first , all those things are fed by it

[@leehedges1120]

You may want to check the ignition switch on colume

[@joonaspulkkinen6369]

That OVP relay seems to be a trucktech cheap garbage. I tried one on my 320CE as originals were on backorder and it failed in one day. It was like key in 2 position all the time without the key being even in the ignition. My original failed to start the fuel pumps when warm. After replacing with an original one, no issues starting.

[@NotEconomicallyViable]

I'll have to stump up the cash for an original then

[@aslandama]

I'd start with engine earth points, even if they look ok I'd still strip and clean them.

[@jamesstuart137]

Italians and Car electrical systems are usually not a good fit😂. I'm hoping you prove that theory wrong..

[@philtowle4683]

Isn't that the screenwash resevoir the rust is under? Don't get that mixed up with coolant resevoir or your paint is going to look even worse.

[@NotEconomicallyViable]

It is indeed haha. I’m always naming things wrong.

[@smurfsmurf2295]

Could even be ignition fault same thing happened to me all dashboard lights were on

[@speedonwheels]

With the engine loom falling apart, l would get a loom made up and replace the one in the car for safety as if you get old loom shorting out that could lead to a fire.

[@smurfsmurf2295]

Yes mate your back

[@teamangie2051]

I'm so terrified for when mine goes wrong. I have an inline six m103. It's been pretty reliable so far, touch wood, but I'm dreading the day when electrics go wrong

[@NotEconomicallyViable]

What year is yours? I think it’s only the ‘91 - ‘96 models that had the messed up wiring

[@teamangie2051]

@@NotEconomicallyViable thanks for the words of comfort 😂😂😂. I have an early model. An 89. I heard a rumour too that South African models never got the biodegradable harnesses because well, we don't care about the ozone 😂

[@ep4no]

You would make a good Ben Mitchell

[@VSTV1993]

Looks like its shorting on igntion side BUT a short in another curcuit can cause all sorts of misterious issues... i'd be lost with this for sure

[@neilhampson2843]

Good to see you back in action. Body shops only work in £500s as a base line price,or multiples of that. The Mercedes look like it could be a bit of a nightmare. I am not the best when it comes to wiring, the only thing I would suggest is pull out fuses until the dash lights go out then find the circuit that corresponds to that fuse. Grounds are the easy thing to start with. Good luck with it.

[@bobbyrayofthefamilysmith24]

I've had body work done for less than 500

[@AlanRafferty]

Crankshaft position sensor has been incorrectly fitted...

[@NotEconomicallyViable]

What's the correct way to fit it?

[@bikeman123]

Got to love internet suggestions

[@andrewandronicou4280]

Taken on a nightmare by the looks of it. Good luck enjoy the vids.

[@bobbyrayofthefamilysmith24]

No looks good car better than the nasty lemon machine I bought from a horrible backstreet garage when I ask for money back due to problems he come out with hammer and threaten to kill my family. Police not help

[@MiracleMitch]

Sounds like a Frankenstein's Monster of electrical issues. A full electrical inspection is going to be needed loom by loom, earth by earth. Sounds like nothing much mechanical is needed relative to the electrical side. To have ALL dash lights without the key in suggests an open power source such as alternator or starter motor, disconnect them each one at a time then both to see if the dash changes. Odd things like headlight switches can short and cause odd dash light illuminations. Do the dash lights change if you depress the brake or clutch pedals? There may be several issues combining to produce the, no pun intended, current situation possibly.

[@kennethcroll6972]

its a auto, has no clutch :}

[@MiracleMitch]

@@kennethcroll6972 Hadn't looked but thanks for clarifying Kenneth. Doesn't change anything as there is a brake pedal and my comment was obviously to rule out any circuit interference that is common on W124s. I have worked on several Mercedes of the 90s and early 00s changing looms etc. which are a very weak point.

[@donnyjarrell131]

Step 1 pull engine step 2 small block Chevy step 3 reliable 🤘big thumbs up from America 🇺🇸

[@itssshana335]

Hello Nino. I hope you sorted your wiring issue. If not read this. I have the same car and one thing I know fails after this many years is the ignition switch. This switch powers the car and puts everything off. yours seems not to be working perfectly. I would check that first. things ought to be off when the key is off. but yourself remain on. that's why your battery drains coz the car remains on so long as battery is connected. You ignition tumbler is also a fail issue after so many years and can leave you stranded one day. I would change it too if indeed your ignition switch is dead. once sorted your wiring can also be removed one day, peeled and repaired even by yourself. I did mine with just insulating tape and now its 6 years since i did it and it works perfectly. once you get the hang of it then this is one of the simplest cars to understand and repair. if you want a video on ignition change then PM me.

[@williamengland1347]

Looks like the wiring loom is the problem

[@mattinwinkymg]

im ten minutes in and my diagnosis is a bad ground to the ecu. now lets watch the rest and see if I'm right

[@anakinskywalker4113]

Mmm the good old Mercedes biodegradable wiring. Most likely you will need a whole new wiring loom. That sounds to me like it’s a dodgy wiring loom from OS your friend got. As a mechanic these are getting to that age where it is a rats nest. I have replaced a wiring loom on a few cars and it’s not a fun. Good luck with this one.

[@petershepherd6889]

Friend of mine had a w124 estate with biodegradable wiring. He set about replacing the engine wiring loom making up sections as he went along but unfortunately he made a right mess of it and couldn't get the car started.I got the job of sorting it out and after a lot of investigation I found two wires in a multi pin plug crossed over.put back as it should be and happy days. Once running the Aircon wouldn't work properly so got it regassed and put gauges on it and head pressure was bonkers. Condenser fan was running backwards so had to sort that one out as well. Next problem was the engine ECU went AWOL and wouldn't run on all cylinders so another ECU was fitted.

[@anakinskywalker4113]

@@petershepherd6889 I replace the wiring looms on my customers cars with a brand new one from a company called delfi which is Specific for the Australian market. They aren’t cheap at around £450-600 for the parts plus at least 10 hours labour to fit the darn thing. As for the ECUs I usually get those refurbished for £150 as a used one is pot luck if will talk to the car. All in all it cost my customers about £1200 or for me to do the job. I would do 2-3 cars a year. They are an absolute pig to do. I normally refer them to my contact who is an auto electrician to do the work. I only take on the relatively easy ones.

[@bobbyrayofthefamilysmith24]

There cars are fantastic definatley worth saving

[@Tinkermatt]

That book is 63£ on Amazon really ??? Is that how much you paid

[@NotEconomicallyViable]

Yeah

[@charlietraquair6866]

Perhaps this can offer some inspiration pal

[@J.F.K.O]

I never liked the design of the w124 and it is a minor detail that puts me off. The tail lights i don't know why but in my mind they somehow ruin the whole car for me.

[@aadd3538]

What ever happened to this Mercedes. Do you still have it?

[@limjamrace]

Everything is getting more and more complex with wiring here..I don`t have a clue with modernish ECU`s and so forth ,but i am thinking of a shut down immobiliser ..The main thing is the main wiring loom which you have had most comments to replace before anything else..Change that and seek out the vehicle immobilser would be my approach

[@NotEconomicallyViable]

Cheers David, I’ll give that a go

[@Don1981]

putt bonnet in service stand lots more room

[@rudolphbondefangerer5513]

Still, it is an example of the last real MBs ever built, and not rusted out, she need saving. Nothing after the 124s would pass the smell test from the time they made cars. Not as brutal as the fall of Toyota, but still.

[@whitemonkey7932]

That's a nightmare mate....i'd get rid...better not fall out with the neighbours, they could make life difficult with non road legal cars on the highway.

[@bobbyrayofthefamilysmith24]

Good project worth saving. Fk neighbours

[@terrywilkins5266]

I take it that this car is too early for an OBD socket.

[@NotEconomicallyViable]

It's got OBD 1 - I've just bought a scan tool for it, so will plug it in and see what it says

[@jadynwilliams-hazleman2104]

Haha Mercedes knew they would brake down regularly so they designed the bonnet to open up that far haha

[@mickbucknell6290]

BCM module is corroded.

[@simonshurmer9470]

Im pretty sure this car has a biodegradable wiring loom

[@NotEconomicallyViable]

Yep 😬

[@davidnorman7948]

@@NotEconomicallyViable oops, great car shame about the bio degradable wiring good luck

[@zgpm7031]

How old are you mate?

[@bobbyrayofthefamilysmith24]

The funny thing is this clapped out old car in this state is still superior to any brand new American car. Hilarious

[@Mahmoud.Jehad.Nassan]

if the wiring is the degradable ones you are doomed

[@robjeavons5982]

Have a mobile merchanic to check with computer

[@ollieox4176]

Think the cars haunted bro

[@ollieox4176]

Have you tried an exorcism

[@bikeman123]

Id start by removing that crap chinese relay you fitted.

[@jmjmservices]

Could be a bad earth strap to,chasis

[@NotEconomicallyViable]

Cheers, John - will take a look into that