1963 Mercedes Benz 190DC Fintail. First start of 2025.

[Dyslexic Viking]

Thank you both, then I have something to start with in the troubleshooting.

[Dyslexic Viking]

Have looked a bit at the electrical on this now to find the charging problems. Charged the battery yesterday and it still held power and it started instantly, so I don't think it's the battery.

So since the alternator is charging, there must be faulty wiring. So I removed all the tape on the wires by the charging relay and was greeted by this.

Someone has hacked into the wiring here. The yellow wire that comes out of the yellow connector that I have marked with a red arrow seems to go directly from the alternator to the starter and then to the battery.

The point on the starter where the wire met below marked with red arrow.

 

This is strange as the wire from the alternator does not go through the charging relay. So a look in the owner's manual and fortunately there is a wiring diagram there I can understand.

24 is the charging relay and 25 is the alternator and 26 is the starter.

So according to what I see, there should be no direct wire from the alternator to the starter, but it should go through the relay before the starter.

So after studying the alternator it has and pictures of the original alternator for these, I am sure that the alternator it now has is not original, which explains the haced wires and why this does not go through the relay.

So what should I do? can I directly put up a new wire from the alternator to the starter where I'm pretty sure the yellow wire goes? or are there other things I should do instead? Advice is needed.

[RayMK]

This may or may not help, but maybe yours has been wired in accordance with generic practice as per the diagram below.  If so, and the battery continues to hold its charge, it starts ok and there's no constant electrical drain when switched off, then I'd just make sure whatever hacked wires are there are in good condition.  With everything switched off, is there any arcing when connecting/disconnecting the battery?  It's an old car so it should not be drawing current unless it has a clock, unlike moderns which have anti-theft and other systems always active.  When my Ginetta had overnight battery discharge problems, I fitted a battery isolator at the battery terminal so that it could be easily isolated overnight.  The continuous battery drain on that heap was caused by a faulty alternator.

[Mr Pastry]

Someone may have modified the wiring, but if was working before, don't try and alter it.  

Are you sure that wiring diagram shows an alternator, and not a dynamo?

You say you have charged the battery and now it starts.  That doesn't prove much.  Disconnect the battery, leave it 24 hours and see if it still holds the charge.

You say the alternator is charging, how do you know that?

I suggested an alternator test yesterday.  If you don't want to do that, okay, but it might tell us something.

 

 

 

[Justwatching]

12.7 volts at idle is suspicious, but as another poster said, you would need to take another reading under load to know for sure. 

 

[Dyslexic Viking]

The charging hassle.

I think it had an alternator originally, but I can't guarantee that. I have measured full charge voltage on the contact on the alternator and in the joint on the wire that goes from the alternator, now it is about 13.8 V.

And I have taken the test suggested here. This has no rev counter so at high revs with light on and heating fan on I get 12.06 on battery terminals with everything still on but at idle I get 11.6, when everything is off I measured 11.4 and when the engine was off I measured I 12.76.

Put the battery on charge afterwards and it was surprisingly full.

I don't understand anything and this is too much for my head, because in my head it's easy when a battery can be charged with a charger and keeps power then that's fine but if it can't get charge voltage then there's something else wrong. 

I'm almost tempted to switch to a new battery and new universal alternator with new wiring. As they seem easy to connect, but saying so, some new problems will probably appear and which I am too stupid to solve. So not sure what to do.

How complicated the charging/battery troubleshooting is makes me in a bad mood, but at least something positive has happened. The order for seat belts and mounts that appeared to be canceled was not and I received them today so that's a problem solved. 

[Justwatching]

1 hour ago, Dyslexic Viking said:

The charging hassle.

I think it had an alternator originally, but I can't guarantee that. I have measured full charge voltage on the contact on the alternator and in the joint on the wire that goes from the alternator, now it is about 13.8 V.

And I have taken the test suggested here. This has no rev counter so at high revs with light on and heating fan on I get 12.06 on battery terminals with everything still on but at idle I get 11.6, when everything is off I measured 11.4 and when the engine was off I measured I 12.76.

Put the battery on charge afterwards and it was surprisingly full.

I don't understand anything and this is too much for my head, because in my head it's easy when a battery can be charged with a charger and keeps power then that's fine but if it can't get charge voltage then there's something else wrong. 

I'm almost tempted to switch to a new battery and new universal alternator with new wiring. As they seem easy to connect, but saying so, some new problems will probably appear and which I am too stupid to solve. So not sure what to do.

How complicated the charging/battery troubleshooting is makes me in a bad mood, but at least something positive has happened. The order for seat belts and mounts that appeared to be canceled was not and I received them today so that's a problem solved. 

Chin up, you've made progress. 

The battery holding full voltage, being able to start the car, run electrical accessories, and still be in a good state of charge afterward suggest that it's fine. The voltage readings taken at the battery during running definitely show it's not being charged. If you're getting charge voltage at the alternator, then the problem must be in between the alternator and battery. Maybe inspect connections and use your multi-meter to test cables for continuity next? 

[Mr Pastry]

If I understand correctly,  you have 12.7 volts across battery with engine and everything off.

Then with engine idling - 13.8 volts coming out of alternator?  that sounds reasonable and suggests alternator and regulator are working.  You should also see about 13.8 at the positive battery terminal - if it is less, possibly a bad connection somewhere between alternator and battery.  

[Dyslexic Viking]

Yes, I have 12.7 volts on the battery and measure 13.8 volts on the connection on the alternator.

And forgot about it, I tried to stretch a wire directly from the alternator to the point on the starter where everything is connected and it made no difference and only gave some sparks when the wire touched it.

Which is a bit strange as the wire from the starter to the battery is the thick one and the starter works well, so maybe I didn't get a good enough contact.

Continuity test is not something I am familiar with but will see if I can learn about it and perform it.

But considering how bad the wire from the alternator is, it might have been best to replace it, as the insulation is completely gone in some places.

[Mr Pastry]

1 minute ago, Dyslexic Viking said:

and only gave some sparks when the wire touched it.

If you can replace the wire from the alternator output to the starter cable terminal, that would be worth doing as the next step.  Alternatively, replace it with a wire directly to the positive battery terminal if it is close.   Then check voltages again.

All this stuff is live all the time, even with engine off, that is why you get sparks!  So always disconnect the battery earth first.

 

[Dyslexic Viking]

2 minutes ago, Mr Pastry said:

If you can replace the wire from the alternator output to the starter cable terminal, that would be worth doing as the next step.  Alternatively, replace it with a wire directly to the positive battery terminal if it is close.   Then check voltages again.

All this stuff is live all the time, even with engine off, that is why you get sparks!  So always disconnect the battery earth first.

 

The battery and alternator are on the opposite side of the car, so going via the starter is probably the best, but it is possible that I can take a temporary lead to the battery for testing.

One thing I also just realized, the alternator that is there now is probably more powerful than the original, so it is possible that the wire from the alternator is not thick enough.

I know I have a 6mm2 cable, need to find out what it can withstand. If not, I'll have to buy something thicker.

[mat_the_cat]

4 hours ago, Dyslexic Viking said:

One thing I also just realized, the alternator that is there now is probably more powerful than the original, so it is possible that the wire from the alternator is not thick enough.

I know I have a 6mm2 cable, need to find out what it can withstand. If not, I'll have to buy something thicker.

You may be onto something there. Imagine trying to force a large volume of water (=more powerful alternator) down a small pipe (=thin original wiring). Potentially made worse if the pipe is damaged and kinked (=poor connections). You have proved there is a voltage drop along the wiring from the alternator to battery, and this is why there is a spark when you temporarily add an additional wire - the current wants to go from the higher voltage alternator to the lower voltage battery, and suddenly finds an easier path to travel than the original wiring.

I hope the comparison with water makes sense in translation.

[Dyslexic Viking]

9 hours ago, mat_the_cat said:

You may be onto something there. Imagine trying to force a large volume of water (=more powerful alternator) down a small pipe (=thin original wiring). Potentially made worse if the pipe is damaged and kinked (=poor connections). You have proved there is a voltage drop along the wiring from the alternator to battery, and this is why there is a spark when you temporarily add an additional wire - the current wants to go from the higher voltage alternator to the lower voltage battery, and suddenly finds an easier path to travel than the original wiring.

I hope the comparison with water makes sense in translation.

Thanks and that makes sense, a good way of explaining this.

I'm going to try a new cable today and see how it goes. Will report later how it went.

[hairnet]

Kim

*Wonders where 10 years went

 

[Dyslexic Viking]

Had the opportunity to spend the whole day today on this and I did. It was a long day and I got a lot done, so there will be a couple of posts.

Started with the most important thing and that was a new cable from the alternator to the starter. After some searching, I found a new roll of 10mm2 cable in my electrical box, this is thicker than the old one, which is probably good. And I chose to have it directly from the alternator to the starter the shortest way, I could have laid it around and next to the body it would have been nicer but would have required over 1 meter of cable. And a little annoyingly, the only shrink insulation I had that fit was blue. But that doesn't really matter much.

And the result? 14.2 volts at idle, 12.5 volts at idle with light and heater fan on, 12.9 volts with light and fan on at higher rpm, measured on the battery terminals.

So the new cable fixed the charging problem, fantastic that's makes me happy.

So after that I removed the old cable that previously ran from the alternator. And it had seen better days.

After that I looked at a blue wire that runs in the same area, not sure what this is and it is not original but I wonder if it is the trigger wire? For the alternator.

I've tried to follow it but can't figure out where it's going. And it has, power while the engine is running. Forgot to measure it while the engine was off. I chose to clean up the cables a bit here and cut away the rest of the excess cable and shorten the blue one and get rid of the bad joints on it.

The result may not have been very pretty, but it is much better than how it was.

Will make another post now as i discovered other problem that could affect charging.

But first I want to thank those here who took the time to help me with the charging problem, I really appreciated that, especially as I can get a little overwhelmed with things I know nothing about. So the help and tips helped a lot.

[Dyslexic Viking]

And this is the new problem I found.

Alternator is really loose.

After some diagnosis, I found out that I had to take it off as the problem was in the alternator mount.

And the problem is that there were plastic linings in the holes for the fastener, probably for vibration damping, and these have disintegrated. Have marked the remains of one of them with a red arrow.

Not sure if these are available new, and I want to have the car drivable now, so after much searching in my boxes of many things, I found a flexible piece of plastic in the right dimension.

After a bit of adaptation and modification, this plastic pice was turned into 2 new liners.

And this worked, there is a tiny amount of slack in the fastener so I didn't get them quite right but it is much better than what it was.

I will look for new bushings for this, if there are I will change to them.

To get better access during this job I removed the air filter so while it was out I cleaned it, which was about time as it was full of crap and after refitting it was filled with new oil.

And I had a starting problem earlier after work on the throotle linkages, it turned out that the valve (don't know the right word) on the air intake, the one in the picture, it was completely closed when the throttle was not applied, so after a little adjusting it was fixed and it now starts instantly without problem.

 I am very happy with how this engine runs, and I feel it has gotten even better after the last oil change.  This was filmed today after all the work. 

 

[mk2_craig]

2 hours ago, Dyslexic Viking said:

After that I looked at a blue wire that runs in the same area, not sure what this is and it is not original but I wonder if it is the trigger wire? For the alternator.

I've tried to follow it but can't figure out where it's going. And it has, power while the engine is running. Forgot to measure it while the engine was off. I chose to clean up the cables a bit here and cut away the rest of the excess cable and shorten the blue one and get rid of the bad joints on it.

At a guess, does this go to the dashboard? It might allow a warning lamp to illuminate with ignition off (or if alternator faulty) 

[Dyslexic Viking]

2 minutes ago, mk2_craig said:

At a guess, does this go to the dashboard? It might allow a warning lamp to illuminate with ignition off (or if alternator faulty) 

It's possible it does but it disappears into the wiring harness and I don't feel like cutting it open to find out. And the wiring diagram I have doesn't have colors on wires so that doesn't help. For clarification. It appears that the blue wire is spliced with an original wire and it is this one that disappears into the wiring harness.

[mk2_craig]

Relying on memory here from when I used to piss around with old Fiestas, those had a small cable (also blue I think) which ran from the instrument cluster to the alternator, it acted as an earth wire for the charge warning lamp when ignition was on with engine off, then with engine running that would send 12v to the instrument cluster and extinguish the lamp because there was 12v on both sides of the bulb and therefore no circuit. Or something like that anyway. It's been a long time. 

[Dyslexic Viking]

40km trip to the post office achieved and the charging seems to be working perfectly.

[Conan]

I think it's impossible (even to non car people) not to feel happy seeing old regular car still in regular usage. Spotting a well used Heckflosse on the road anywhere in the world would certainly make my day.

[Dyslexic Viking]

A small update. I changed the oil on the gearbox and differential today and in total there was almost 1 liter of oil missing and the oil was bad so it hasn't been changed for a long time.

Both new and old gearbox oil was scary thin and the differential oil 90 weight was a challenge to get pumped in.

But now it's done, the next thing is greasing and various other maintenance points. Like oil on the steering box.

'

 

And received a message today that the interior carpets have been produced and shipped.

[Sunny Jim]

Sounds like you've had a good couple of days with the car achieving and making progress - hopefully you're on a roll.

[Dyslexic Viking]

2 minutes ago, Sunny Jim said:

Sounds like you've had a good couple of days with the car achieving and making progress - hopefully you're on a roll.

I hope so, the biggest thing now is the welding, I hope it goes well.

[Dyslexic Viking]

Today is a special day as it is today 60 years since this was first registered in Norway.

But there will be no driving as the seals in the clutch slave cylinder have gone so it leaks heavily now. A new clutch slave cylinder is no longer available, but an overhaul kit is, so it has been ordered.

Hopefully I can get this fixed before the welding in 2 weeks.

[Dyslexic Viking]

Have done a lot of maintenance now. As top up of oil on the dieselpump and steering box etc.

But the greasing was a nightmare for someone with a bad body but got through it in the end. But 4 of the grease nipples it is not possible to get grease in, I don't understand why, I have changed the grease nipples poked inside before that and can't get grease in. After a long time of fighting, I have almost given them up.

The next thing now is the clutch slave cylinder and gaskets are on their way.

[Matty]

1 hour ago, Dyslexic Viking said:

Have done a lot of maintenance now. As top up of oil on the dieselpump and steering box etc.

But the greasing was a nightmare for someone with a bad body but got through it in the end. But 4 of the grease nipples it is not possible to get grease in, I don't understand why, I have changed the grease nipples poked inside before that and can't get grease in. After a long time of fighting, I have almost given them up.

The next thing now is the clutch slave cylinder and gaskets are on their way.

Whatever void it is your trying to grease may be full of old hardened grease. Most of the time you'll get grease in even if it's full cos the hydraulic pressure will just force whatever is in there past whatever sealing arrangement etc is holding it in. Grease can go off like blue tac. I get to spend a lot of time cleaning it out of labyrinth seals of the old machines I work on 😔

[Dyslexic Viking]

7 minutes ago, Matty said:

Whatever void it is your trying to grease may be full of old hardened grease. Most of the time you'll get grease in even if it's full cos the hydraulic pressure will just force whatever is in there past whatever sealing arrangement etc is holding it in. Grease can go off like blue tac. I get to spend a lot of time cleaning it out of labyrinth seals of the old machines I work on 😔

I'm not sure what the problem is but it's possible it's old grease as you say. I have an air greasegun that is powerful and even if I hold the grease head as hard as I can on the grease nipple and the grease nipple is new, the grease comes out on the sides. And holding at the greaseniple in different angles doesn't help.

Motivation on still fighting them is not high as I am not doing well under the car, I need a car lift.

[Dyslexic Viking]

While this has been down, I have had some other work done such as the rear wheel arches. They were full of gravel and after much scraping and cleaning, a lot of surface rust and many old welding repairs appeared. I treated the rust and painted it but since there was so much rust at the start and all the old repairs I didn't feel comfortable putting wax over everything so instead Fluid Film was applied as it has good rust properties and is very penetrating and creeps so it can penetrate the old repairs if they are not completely sealed.

I also tried on the visible parts Fluid film colored black and it turned out well. 

Fluid Film also has the advantage that it is easy to remove if you want to in the future.

And yesterday I got the clutch slave cylinder rebuild kit So then it was time to take it off and fix it.

But it turns out that I had received the wrong parts. It's not the first time I've received the wrong parts from them so I don't like to shop there but they can get some parts for these so that's why I do it.

Those parts are from Frenkit and I have discovered that they have a good website for finding parts and part numbers. So after looking there I know what parts I need for the cluth slave cylinder.   https://www.frenkit.es/en

So without being able to fix the slave cylinder, I realized that I bought a used one last year. It was found and after looking at it, it is either a NOS part or it has been overhauled as it looks very nice and has newer parts on it.

It was then fitted and after a somewhat difficult bleeding of the system, I had a functioning clutch again. And today 24 hours later, this has not leaked and after a drive the clutch works very well.

I dare not say that it is fixed yet and I will try and fix the old slave cylinder and have it as a spare.

The next thing now is that this is off for welding on Tuesday.

[danthecapriman]

Nice job so far. Must admit I’ve never heard of fluid film - might have to have a look for some and see what it’s like.

Cant wait to see it come back from the welders👍