So you enjoy giving bad advice, leading forum members to spend money on unneeded repairs, get frustrated and dump their Mercedes?

A starter should last a long long time if not abused on a well maintained vehicle, well pass 20 years. The starter runs for what? 1/2 sec to 1 sec to start a well maintained W123 diesel. Add up the total number of starts over 20 years and it should be fine and not worn out. On the other hand, if you have to crank for 5 minutes every time to get it started and overheats the starter, it will be toast even if the starter is brand new. Another bad thing to do to a starter is to crank with a weak battery to the point it stalls and you keep trying to start. That heats up the windings and shorts them out and that starter is toast.

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85 300D turbo pristine w 157k when purchased 167,870 July 2025
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

I don't know if the erarlier models have the Neutral Safety Swich Connector inside of the Car in the same Place. But, if you use the Connector to bypass the Neutral Safety Switch and is starts all the time with the Switch bypassed you have found your problem.
Some pics in the thread:
Neutral Safety Switch Troubleshooting 84 300D

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84 300D, 82 Volvo 244Gl Diesel

Hello and thanks for the additional insights!

Update, Yesterday I began a methodical observation routine.
Checked the oil. Needed one quart (10-40 Delvo).
I started the car up in the morning (approx 42F) in Neutral after cycling the glow plugs three times.
The start up was crisp and fast (2-3 seconds).

Propped one side of the car on a curb and checked the underside.
All was clean, starter clean, wire connections looked clean and sound, NSS looked clean and nothing seemed loose or movable by hand probes. Wire harness was clean and snug and sound. Battery cables tight and clean as were the wires.

I took a 30 minute drive and up some highway grades. Lots of carbon soot flushed out the exhaust pipe !

Two hours later after car sat in garage, the hood was still warm, I started it while in Park. I did not cycle the plugs.
After 5-7 seconds of normal starter activity, the engine started normally.(ambient around 48F)

This morning (about 49-50F) I cold started engine in Park after cycling the glow plugs three times.
It started normally with a crisp 2-3 second start time. (same 2-3 seconds as previous successful start ups after cycling the glow plugs).

Went out. Parked.
Car started in park normally again.
Did another task.
Car started normally in Park.
Not sluggish start ups etc.

I was beginning to doubt the NSS since it appeared that the starter was OK, but so far so good.

So, tentatively the car is normal.

I did not check the braided ground strap.

Where is this located in the W123?

I read that sometimes that can cause false starts if not tight, clean etc.

At this point it seems that the cold and perhaps the carbon build up may have been factors.

Aside: cycling the glow plugs in the cold ambient temp. allowed a very fast and crisp start up. Not cycling, the start up was a few seconds longer.

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1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
********************
1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD

Ground strap is found under the drives seat/firewall area...underneath the car....easy to find....

Again at that temperature....there is no need to glow that long....

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I am not giving bad advice, I am simply giving advice on what I've read that the op has posted......sadly no one on here can give the person the right diagnosis with out a visually inspection.....trust me I even have a crystal ball and I can't see it...

Now you may be correct, a starter may last a life time.....if you have personally owned said car from day one and kept a log on how long it has taken to start over the car, the amount of times started...etc...but even a brand new w123 will see excess starting when temps are below freezing....

A start is an electric motor, not made from diamonds, fairy dust, unicorn horns or platinum. That do wear, brushes wear, grease gets old, commuter gets burnt, carbon builds up.....if a starter motor is suppose to last a lifetime I wonder why a blower motor doesn't? It may run more but its not under as much stress....

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My car today would not crank, battery power was fine and all was well except turn the key and nothing not even a click or pop.
Jacked up the car got under it and beat on the starter with a lug wrench, still nothing.
I finally got a piece of wife and shorted the solenoid to the power side of the starter and
sparked a little and the car would crank. Got it home and thought it was the nss, and it checked fine. So I pulled the starter (what a boger to do) and took to the rebuild shop and the bushing were so bad in the front of the starter if it stopped on a certain spot the electric motor (starter) would not energize and there fore it was intermittent. Mine I noticed it acting up a few weeks back. Also my solenoid had seen its better days, it fell apart when I took the wire off it.
I hooked a small lead wire to the side of the solenoid that the key energizes and ran it up top just in case this does not fix it, that way all I do is hit it on the positive side of the battery with the switch on to crank it, if need be. If all goes well for a few weeks I will take the wire off that I added. I hate climbing under a car on a jack with no safety and in the rain. LOL


ETA: what my car was doing is commonly called "a dead spot on the armature".
When the bushings are worn out and the starter intermittently does not crank.

[QUOTE=Rockyriver;3252612]My car today would not crank, battery power was fine and all was well except turn the key and nothing not even a click or pop.
Jacked up the car got under it and beat on the starter with a lug wrench, still nothing.
I finally got a piece of wife [sic]...."


'Nuff said !!!

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1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
********************
1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD

[QUOTE=unkl300d;3252718]LOL,
That should of said piece of wire.
I hate spell check sometimes.

[QUOTE=Rockyriver;3253481]yeah... we'll go with spell check, not freudian slip... wishful thinking?

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

For those who a piece of wife uhmm piece of wire helps to get the starter to crank:

1. The starter solenoid draws about 8 amps.

2. There is no relay and that 8 amps must be carried by the ignition switch, neutral safety switch and wiring in between. Any part of that circuit failing can result in the starter solenoid not engaging correctly.

a. The ign sw and NSS sw contacts can get corroded

b. Wire connections can get loose or corroded

c. The starter solenoid iron core can get moisture inside and corrode and cause it to hang.

Any of the above items can contribute to the famous click but no crank when you turn the key.

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85 300D turbo pristine w 157k when purchased 167,870 July 2025
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

Wow so I guess my comment on that starter was right....boy I must be giving horrible advice.....just had to put my told yeh so in

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Ok, first of all, my W123 is a 1985. Car in question is a 1979.

I had constant starting issues with mine. It seemed to get worse as the temp outside dropped. I checked ground strap and it was fine. I found a loose connection on the large terminal on the starter. It was loose. Wow! I found the problem. Nope. Checked the NSS by checking the wiring on/around accelerator pedal. Checks out good. Checked shifter bushings. They were gone! Replaced those thinking, once again, I found the problem. Nope, still struggling with no start situations. And, mind you, my no start was basically a turn of the key and a slight click could be heard from the starter, but that was it.

EVERYTIME I had one of these no starts, if I jumped the terminal on the passenger side fender (1979 probably does not have this terminal), the car would immediately and always start.

After reading a post on here about wiring in a fender-mounter Ford solenoid to feed a full 12 volts and whatever amps the MB starter requires, I finally did this install and have never had to pop my hood again to jump the fender terminal.

My problem could have been compounded, but this solution worked. And I wish I had done it 2 years ago!

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'85 300D 190K miles
running on B100 Biodiesel since 156K, SCRATCH THAT! I can only find Biodiesel at 1 location in Houston! (not very convenient)

Adding an alternate solenoid sounds like a great idea for those who need a solenoid and don't want the pain of starter removal.

So far my car is acting normally.

I did not have a chance to inspect the ground strap yet. BUSY

Weather is getting a bit warmer this week also. (50 to 60F)

So its still tentatively OK.

This thread will be good for the archives as it revisits some odd symptoms others have had.

__________________
1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
********************
1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD

Satisfying dream huh?

__________________
85 300D turbo pristine w 157k when purchased 167,870 July 2025
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

I have been trying to figure out how the Ford Solenoid would help a defective on the Starter Solenoid.

The only thing I can think of is if the Contacts that connect the Voltage to the Motor were burned up and not working.

But, you would think that the Ford Solenoid would allow a chance for the Motor to Spin before the Gear is engaged.

Attached Thumbnails

 

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84 300D, 82 Volvo 244Gl Diesel