[Jeroen]

Originally Posted by Sutripta

So what are your (technical) thoughts now on the 'zener' matter?

There are three parts/functions to it:

1) Something that limits available current passing through.
2) Something that emits a red light.
3) Something that allows the red light to come on, when main power is cut.

All three can be solved with different technical solutions, but I am not sure if they are all can be solved with one simple (zener) diode.

Rather then to think about it, I will find a way to open it up next week and show you.

Your thoughts on how all three parts/functions?

[Sutripta]

Originally Posted by Jeroen

Your thoughts on how all three parts/functions?

Check how a blown fuse indicator is implemented. (OK, with MCBs maybe irrelevant nowadays. HRC fuses usually use a different (semi mechanical) indicator method).
Adjust for 12 V DC.

Zeners are (constant) voltage clamping devices, and should have no place in this scenario. Unless one is building an electrical equivalent of a Rube Goldberg machine. However there is a 'constant current' version (variation of a FET) once sold by Motorola which can be used to some advantage in this case, but I would say not worth the effort.
Essentially to make the LED glow with limited load downstream, yet not blow it if say the headlights are switched into the circuit.

Regards
Sutripta

[Kartik Deshmukh]

Hello everybody,

Recently I noticed that my e220 W124 is leaking fuel and to make problems worse I found a dead rat inside the car. I took it to a local mechanic and he said it is the leaking fuel pump, can the fuel pump be mended or it needs to be replaced? And also should I check the relay as well?
Hoping that someone would help, as I bought the W124 as my daily driver. Thank you.

[Jeroen]

Originally Posted by Kartik Deshmukh

Hello everybody,



Recently I noticed that my e220 W124 is leaking fuel and to make problems worse I found a dead rat inside the car. I took it to a local mechanic and he said it is the leaking fuel pump, can the fuel pump be mended or it needs to be replaced? And also should I check the relay as well?

.

It depends what W123 you have. In general the electric petrol pums can not be repaired. I believe some of the earlier diesel membrane pumps maybe.

It all depend. Can you take a photograph?
If you have rats in the car, he might have bitten on the fuel lines. On both petrol and diesel version most of these are metal tubing running from the fuel tank at the back to the engine up front. However, the connections to the tank are fuel hoses and also near the engine you will find hoses, rather than tubing. Irrespective of your current leak, or rats, these hoses perish over time and need replacing after 30-40 years. So make sure it really is the pump and not something else.

There is no reason to replace the fuel pump relays, if everything, other than the leak, is working fine.

Good luck

Jeroen

[Kartik Deshmukh]

Originally Posted by Jeroen

It depends what W123 you have.
======
There is no reason to replace the fuel pump relays, if everything, other than the leak, is working fine.

Good luck

Jeroen

Hello Jeroen,

I have attached some images and also pin pointed from where the leak is happening. So I don't think it's the hoses, maybe a faulty fuel pump? My car is a 1997 model e220 W124.

Thank you

[Jeroen]

Originally Posted by Kartik Deshmukh

I have attached some images and also pin pointed from where the leak is happening. So I don't think it's the hoses, maybe a faulty fuel pump? My car is a 1997 model e220 W124.

always a bit difficult to see on a photograph. I do not see any obvious wet spots. I do see a piece of hose, hose clamp, bajonet bolt with a copper ring. All of that can leak if not tightened properly. Try and switch on the pump, (usually switching on the ignition will do) and see if you can see where the actual leak is.

Anything coming from the above should be fixable without having to replace the pump. If it leak from somewhere else on the pump you might have to replace the pump. This looks like a sealed pump, so not much you can do.

Good luck

Jeroen

[stormsearcher]

Originally Posted by CLYDE

Hello everybody,

The battery on my W124 is getting on in years (an Exide fitted prior to my getting the car in December 2016) and since I run her only over the weekends to keep the fluids going, I need to bench-charge the battery prior to an outing. I need to know if it is OK to connect the charger WITHOUT disconnecting the car's wiring from the battery terminals. I used to bench-charge my TATA Indigo without isolating the battery, but modern-day cars require the battery to be disconnected prior to bench-charging, hence this query.

Hope someone can help. Thanks in advance.

CLYDE

I have a question. Why do you need to charge the battery every week? Even if you are not doing many runs, the battery will not discharge so fast. If its doing so, there is another problem with the car.

[Kartik Deshmukh]

Originally Posted by Jeroen

always a bit difficult to see on a photograph. I do not see any obvious wet spots. I do see a piece of hose, hose clamp, bajonet bolt with a copper ring. All of that can leak if not tightened properly. Try and switch on the pump, (usually switching on the ignition will do) and see if you can see where the actual leak is.



Anything coming from the above should be fixable without having to replace the pump. If it leak from somewhere else on the pump you might have to replace the pump. This looks like a sealed pump, so not much you can do.



Good luck



Jeroen

If I fill petrol it still leaks without even switching on the pump(switching on the ignition), I don't know much about it but that is for sure it's a sealed pump can't do much. I have a video that shows the exact place from where it leaks. Going to take the car to a W124 specialist,that is what I have been told. Hoping for the best.

Thank you

[DudeWithaFiat]

Hello guys,

Back here with another problem.

So my W124 (250D - OM605) hasn't been cooling very well. The cooling fan spins, but it wouldn't spin faster when the car starts heating up. So, when the car is moving, the temp guage stays around 90, but if you are bump-to-bump traffic for a long time, it creeps to 100 or above. After searching about it on the internet, I tried to spin the fan with my hand when the engine was not running, it is holding its resistance. Does it mean that the Fan Clutch is alright and it might be the switch that is gone?

Car is located in Pune.

# AC cools well.
# The cooling fan starts spinning at a moderate speed as soon as the engine starts running, but the speed never increases.

[Frankenstein]

Its the clutch fan assembly , i had the exact same issue, get it changed in the service center. They will inspect the whole cooling system. Outside mechanics wont take the pain to identify .

[Jeroen]

As far as I know the W124 clutch is similar to the W123. It is an electo-mechanical clutch operated via a thermo switch. With the engine at standstill and cool you should be able to push the fan freely. There should be only a little friction. With the engine running that little friction is enough to have the fan running too, but not as fast as the engine. When the cooling liquid reaches a certain temperature the thermo switch closes and, the clutch engages and the fan turns as fast as the engine.

First, check the fuse! If that is ok

Are you able to turn your fan by hand with the engine off and cool? If so, the clutch can be checked very easily. With the ignition on, short the thermo switch. You should hear the clutch engage and the fan will be held in place solidly. Alternatively apply 12 V directly to the clutch.

If that works, the next suspect is the thermo switch itself.

You might also want to check the wiring for any visible damage. Some of it runs close to the fan. Also, if I recall there is a connector on the wires leading to clutch assembly. Make sure it is clean and tight..

Good luck

[DudeWithaFiat]

Originally Posted by Frankenstein

Its the clutch fan assembly , i had the exact same issue, get it changed in the service center. They will inspect the whole cooling system. Outside mechanics wont take the pain to identify .

Originally Posted by Jeroen

As far as I know the W124 clutch is similar to the W123. It is an electo-mechanical clutch operated via a thermo switch. With the engine at standstill and cool you should be able to push the fan freely. There should be only a little friction.

Good luck

Thank you guys. They say it is called the 'viscous fan', and apparently it is driven by the engine and its speed regulated by a viscous/visco/fan clutch that lets the fan spin faster depending on the temperature.
So, I took the car to the mechanic. After some visual checks, he used some kind of an electronic meter, dipped in the coolant, showed me the reading and said the water content in the coolant is too high. I looked inside the coolant reservoir and it looked like 'just' water to me. May be the previous mech pulled a fast one on me? So, we now filled a coolant and till now, the temperature hasn't gone too high, but then I haven't driven in bumper to bumper traffic after the change, but I feel its better now.
He said that the fan will start spinning faster only after the temp crosses 90 or so since the normal operating temperature of these engines are 85-90. I'll update the next time I get stuck in traffic with my W124.

[Jeroen]

Could well be a viscous fan too. And yes that is how they work.
The cooling liquid temperature is dependent on the thermostat installed. It is not unusual on the W123/124 to see it going towards the 100oC in slow traffic. Not a problem.
Jeroen

[GTO]

Spotted this W124 with an unusual set of rims in Parsi colony. Watchman told me it's a daily driver. While the style of the alloy wheels is a love-or-hate (wouldn't be my choice), there is no denying that this car had incredible presence . I passed it, then took a u-turn, parked on the opposite side and walked up to check her out. Had a couple of nicks / misses (e.g. missing star at the back), but overall, she looked beautiful. Child seat always tells me it's an informed owner.

[BANDHAV]

Originally Posted by GTO

Child seat always tells me it's an informed owner.

Belongs to Cyrus Dabhar, being a bhpian (ex), you expect him to be informed.