You're ignoring the basics and chasing your tail .

If the starter sometimes works but not when you jumper it directly at the solenoid, the solenoid is bad plain and simple .

All the other things may or may not need attention further but you're wasting time here .

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-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

Here is a video to show everyone what is going on. It explains much better than words:

https://youtu.be/p7XmFciooeo

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'80 300SD - '83 240D - '00 E55 AMG - '02 G500

Bump. Anyone have any input on the video above? Stood outside in the rain for 20mins today with the screwdriver and the starter finally turned. Need to get this fixed.

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'80 300SD - '83 240D - '00 E55 AMG - '02 G500

How many times do you have to be told you have a bad solenoid before you replace it? You can wish a problem away, but it isn't going away unless YOU do something about it!

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]

So based on that video above, you can 100% say that is a bad solenoid?

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'80 300SD - '83 240D - '00 E55 AMG - '02 G500

Solenoid or motor. You've eliminated everything else by using the screwdriver. Since you have the solenoid clicking, but not pulling in all the way (clunk), it would seem highly likely that the solenoid is your culprit. The only way you're going to find out is to replace the solenoid, or the whole starter. Your choice.

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]

That's not the solenoid clicking. That's the glow plug relay clicking on the other side of the bay. Everytime I hit the key or jump it with the screw driver, the relay clicks.

__________________
'80 300SD - '83 240D - '00 E55 AMG - '02 G500

If you're manually jumping the solenoid and it isn't pulling in, look no further.

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]

Only true if the grounds are sound.

__________________
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

They've been checked and cleaned a thousand times over.

__________________
'80 300SD - '83 240D - '00 E55 AMG - '02 G500

Just checked the date of your first post; it appears you have been into this issue for over two months and counting. I'd challenge you to take a piece of paper and start logging the number of hours you have spent and are spending. It would look something like this:

1. Monday, posted on peachparts forum for two hours.
2. Tuesday, climbed under car and checked solonoid and wiring 1.0 hour.
3. Wednesday, posted on peach parts forum for 1.5 hours.

You get the idea; now total up the hours and multiply by 50 as in 50 dollars per hour. Your time is worth a minimum of 50 dollars/hour. In addition there are 168 hours in a week. You've been at this around nine weeks so take nine times 168 = 1,512 hours you've gone without the use of a reliable car.

This is why perhaps taking the car to a competent auto electrical repair shop might be a GREAT investment of your time and money. In two hours they may figure out what you haven't figured out in over two months.

If you do take it in, be sure and ask what their basic diagnostic fee is, then hold their feet to the fire on it.

Some years back, I used to know the owner of a very competent auto electric repair shop. His specialty was Mercedes; he could figure out a problem in one hour that would have taken me WEEKS to figure out. He told me German Electrics are not easy to diagnose...........

That settles it then. Thanks.

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'80 300SD - '83 240D - '00 E55 AMG - '02 G500

Husky, that would be a great idea if the issue was constant. It might go weeks without having a no start. I'm not going to let it sit at my mechanics that long and my mechanic doesn't want a car taking up valuable lot space for something that might not happen for a month.

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'80 300SD - '83 240D - '00 E55 AMG - '02 G500

I had a similar situation like post 45.
Turn the key to start, the the starter would click but no crank. Then I'd jumper it and it would start right up. Then turn off the ignition and turn it to start and it would start right up. Changed the ignition and solved the problem.

Not necessarily your problem, but giving you another idea. You can always try rigging a remote starter switch to see if the ignitions the problem.... just an idea

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1974 240d
1983 240d -sold
1989 420sel with om606
1994 s350 turbodiesel - sold

Previously suggested post # 31.
Explicit instructions and FSM link were provided in that post.
Could even be left connected and zip-tied out of the way to avoid using a screwdriver to jump the solenoid when another random no-start situation exists.

__________________
78 W116 300SD 'Desert Rose' new as of 01/26/2014
79 W116 300SD 'Stormcloud' RIP 04/11/2022