[MBGraham]

Wife said that yesterday, she had no start when she turned key. But then on second try it started. She went shopping and it started after each stop.
This morning, she went to go out and the car would not start. Starter dead. Turn key to start position - no click no nothing.

I know that no-start is not an uncommon problem on this forum, so did some of the threads.

I first checked battery and although it tested out Ok voltage wise, it was not so good on a load tester. It was 10 yrs old, so as a first step, I bought a new battery. So now we have about 12.56V and climate panel displays 11.6V. This of course with engine not running!

I tried jumpering the starter relay A-C. Still no starter. With key on, I do see a small spark when inserting the jumper. So some power getting there. Checked resistance D-B - both relays about 85 ohms

Next, I replaced the entire K-40 module with a new one that I happened to have as a spare. So there should now be a new starter relay as well as all new fuses. Still nothing. Checked all fuses, and they are good.

So, what to do next before I have car towed to dealer?

 

[mrboca]

Do you hear any noise when you put a jumper on the "contacts" side of the starter relay with the key in position 2? Just to make sure, I believe it is 30 and 87 marked terminals.

Maybe a bad / corroded ground strap on the starter to power the motor.

Checked resistance D-B - both relays about 85 ohms

What relays ?

 

[MBGraham]

No sound when jumpering starter relay from A-C with key in 2and position.

I have a spare starter relay (and complete K40). Both starter relays measure about 85 ohms from B-D.

Maybe I can test relay in place? So if I attempt start, I could confirm the relay closes. Trying to find diagram to see if the wires that go to A & C are accessible from top of K40.

If the relay closes, then likely problem with wiring to solenoid or solenoid?

May have to go under car and find the starter & solenoid and test there?

All suggestions welcomed

 

[mrboca]

Here is a partial diagram of K40. K2 is the starter relay which is controlled by the ECU. The Violet wire is the wire that goes from the contact of K2 to K40 connector A1, pin 6 then to the solenoid.

All you need to do is to look for 12V at that pin where violet wire is connected when someone cranks the engine.

 

[MBGraham]

Thanks.

I had wife back, so she helped! I hear a click from relay when she attempts a start. I also get 12+V on the violet wire that is just to the right of the 40A fuse. Presume that is the wire that goes to the starter solenoid.

So sounds like a starter or solenoid problem. Maybe wiring or grounds, but after 22 years, probably starter/solenoid. Now I have to find just where they are and if accessible for an 80yr old

BTW, Just been through this with my 85 300D. Starter died in my garage. Was going to get CAA to tow and then do a DIY replacement with help from young friend with lift. So I bought an ACDelco reman Bosch starter from Rock. Then friend had another car stuck on his lift so instead had my car towed to local shop. They put in the ACDelco starter. But it would not run. Basically dead even with power applied directly. How can they send out untested starters? I took the old original starter to a local autoelectric shop, and they rebuilt it and tested it! (all new parts except for nose cone!) Then shop installed that. Faulty starter just arrived back at Rock today. Hope to see refund soon!

And now I have another starter problem

 

[mrboca]

In these cases, a gooseneck camera would be very useful. There is a copper multi strand jumper wire between the solenoid and the starter itself. that tends to corrode and disintegrate. Unfortunately it is not easy to replace it at home but certainly can be done at a repair shop. Or, it may have worn brushes who knows ?

 

[MBGraham]

I have one of those inspection cameras. I presume I will first have to remove the bottom shields to get it in there. If I can reach the starter terminals, it would be useful to check that 12v is getting to the solenoid from the battery and from the starting circuit.

 

[khomer2]

MBGraham,
A recent post on this older thread popped up - not sure if it has any tie-in to your situation.

post#8

W210 won’t start.....sometimes

Hello everyone! I just bought a 2001 E320 sedan this morning at 6am. I owned a 99 E320 wagon years ago and regretted having to sell it, so I have been hunting for one since moving to the west coast a month ago. I really want a wagon, but I need a car for work, and this sedan seemed really nice...

www.benzworld.org

 

[MBGraham]

MBGraham,
A recent post on this older thread popped up - not sure if it has any tie-in to your situation.

post#8

W210 won’t start.....sometimes

Hello everyone! I just bought a 2001 E320 sedan this morning at 6am. I owned a 99 E320 wagon years ago and regretted having to sell it, so I have been hunting for one since moving to the west coast a month ago. I really want a wagon, but I need a car for work, and this sedan seemed really nice...

www.benzworld.org

It is possible that there is a wiring issue on the wire that runs from the starter relay to the starter solenoid.

To check that, I need to get under car and see if the solenoid gets 12v when the key is turned. I need to find out how practical that is for me at home with car in driveway, seeing car will probably have to be towed to shop for starter replacement.

I have a question that I guess I should go out and try - When I want to move my old Benzes without starting engines, I just put them in Neutral and can push them. Does that work on the W210? My car is not in ideal location to work on! And if taken to shop they will need to push it onto hoist))

 

[mrboca]

I have one of those inspection cameras. I presume I will first have to remove the bottom shields to get it in there. If I can reach the starter terminals, it would be useful to check that 12v is getting to the solenoid from the battery and from the starting circuit.

You could measure resistance between chassis ground and the violet wire. You should read a very low resistance (the resistance of the solenoid coil). If open, then you know 12V is not reaching there, or a ground issue for the solenoid.

You should be able to move it in neutral (very carefully).

 

[khomer2]

It is possible that there is a wiring issue on the wire that runs from the starter relay to the starter solenoid.

To check that, I need to get under car and see if the solenoid gets 12v when the key is turned. I need to find out how practical that is for me at home with car in driveway, seeing car will probably have to be towed to shop for starter replacement.

I have a question that I guess I should go out and try - When I want to move my old Benzes without starting engines, I just put them in Neutral and can push them. Does that work on the W210? My car is not in ideal location to work on! And if taken to shop they will need to push it onto hoist))

Yes, that will work, but before you do that follow mrboca's call in post #10 so you can get a better snapshot.

 

[MBGraham]

You could measure resistance between chassis ground and the violet wire. You should read a very low resistance (the resistance of the solenoid coil). If open, then you know 12V is not reaching there, or a ground issue for the solenoid.

You should be able to move it in neutral (very carefully).

I measured the resistance from violet conductor to ground. It's in 1.5-1.8 ohm range depending on what I used for ground. I presume this means that the wiring to solenoid is intact. But interesting that the solenoid makes no clicking sound when the key is turned.

 

[mrboca]

It appears that there is an issue with the ground strap which has become resistive. Photo from a W163 thread , with respects to 43sqd. In any case, replacement is required after confirmation.

 

[MBGraham]

It appears that there is an issue with the ground strap which has become resistive. Photo from a W163 thread , with respects to 43sqd. In any case, replacement is required after confirmation.

Don't understand. What would the resistance be if there was no ground strap problem? From what I read on-line, it says that resistance should be less than 5ohms. And I only have 1.5ohms using the chassis ground adjacent to the K40.

 

[mrboca]

In the picture above, the solenoid receives start cable, battery cable and the ground. So the solenoid connection is OK, and probably it moves to close the contact for the starter motor. If the starter motor contacts are intact, and the ground strap that supplies ground to the motor is intact, the starter motor should operate as long as the solenoid has current flowing through it. If the ground strap has high resistance, the starter will not budge.

Now, does the solenoid make a noise when power is applied ? I don't know. It is also possible that the power terminal to the solenoid is corroded and presenting a high resistance. These can be visually inspected. If the connections look fine and tight, then probably it is the aging of the starter motor brushes.

 

[Witek_M]

I am not sure why copper braid is called ground strap. Starter is bolted to the engine that is grounded or at least should be. Copper braid carries positive current from terminal 30 (big lug) through relay (solenoid) to motor brushes.

There are two stages of starter operation. Phase 1. Electromagnetic force moves starter gear to engage teeth of the ring gear (flywheel). Phase 2. Round disc inside relay (solenoid) connects terminal 30 to copper braid. Motor begins to rotate.
For those needing visual here it is.

 

[mrboca]

I am not sure why copper braid is called ground strap. Starter is bolted to the engine that is grounded or at least should be. Copper braid carries positive current from terminal 30 (big lug) through relay (solenoid) to motor brushes.

There are two stages of starter operation. Phase 1. Electromagnetic force moves starter gear to engage teeth of the ring gear (flywheel). Phase 2. Round disc inside relay (solenoid) connects terminal 30 to copper braid. Motor begins to rotate.
For those needing visual here it is.

Yeah, I stand corrected. It is the starter motor power strap. The picture above was probably marked by 43sqd incorrectly. In any case, if it is damaged by corrosion it will be resistive to turn the motor, just like worn brushes / copper rings. I remember the old Honda I had which had dead spots on the starter brush / ring contacts. If the engine would not crank, a tap with a hammer was usually persuasive enough to make it start. With those cars, you could actually reach the starter from under-the-hood.

 

[brooktre]

I agree with the presumption that the starter motor power strap is the likely failure. I had to replace the starter on 2 of my W210s, and both had the failed strap. I don’t know about a non 4Matic, but it is fairly difficult on a W210 4Matic as you have to drop the exhaust.

 

[Deplore]

Non-4matic (regular RWD) is cake. Two bolt is all thats holding it, and then you just play tetris to get it out.

 

[MBGraham]

Non-4matic (regular RWD) is cake. Two bolt is all thats holding it, and then you just play tetris to get it out.

Please to hear it is a piece of cake

Just checked WIS - They say to disconnect engine mount and raise engine 20mm, presumably for RWD & 4-matic. Is that not really neccessary?