Check your battery terminals.

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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

ok friends I got the windows working. Fuse #12 had a hairline crack. This didnt solve the starter issue. Lately the car has accidently sat withthe key in the ON (glow plugs on) position several times in the last few weeks while we work on it. Could this have damaged a relay somewhere? When I turn the key nothing happens at all at the starter. Its not the battery contacts, their tight and the car is getting electrical power and when i do attempt to crank it none of the lights dim or anything so the cars just not sending power to the starter. Im beginning to suspect that its the ignition switch itself

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1981 300SD 512k OM603

Clip on a Remote Starter to you Starter Solenoid and a Posative source of Voltage and see if it the Starter will crank. If it does there is a good chance it is the Neutral Safety Switch (if your car has an Automatic Trans).

I do not know if the follong info will apply to your 300CD or not:

No Cranking explanation from 240D3.OT mbworld.org.
http://www.mbworld.org/forums/diesel-forum/313982-no-crank-1984-300d.html
“First make sure the selector is in P or N. Cycle through all the gear positions and try in N.
In front of the battery is a small rectangular box. Use a jumper wire to jump from one of the large posts to the small post with the purple wire. If it cranks, you've got an issue with the neutral safety switch or the ignition switch.


Above the accelerator pedal is a 4-wire plug with a harness that runs down to under the accelerator pedal and to the transmission tunnel. Unplug it, jumper across the two purple wires in the female plug and try to start again. If it starts, you need a NSS.”

I do not know if your cars wiring is the same but I got part of this quote from another Forum concerning a no cranking problem with an 84 300D.
“First make sure the selector is in P or N. Cycle through all the gear positions and try in N.
In front of the battery is a small rectangular box. Use a jumper wire to jump from one of the large posts to the small post with the purple wire. If it cranks, you've got an issue with the neutral safety switch or the ignition switch.
Above the accelerator pedal is a 4-wire plug with a harness that runs down to under the accelerator pedal and to the transmission tunnel. Unplug it, jumper across the two purple wires in the female plug and try to start again. If it starts, you need a NSS.”

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84 300D, 82 Volvo 244Gl Diesel

The Glow Plug Relay timer stays on for about 30 seconds and turns off. After that you would need to cycle the Key to start over with the Glow Plug. So I would say little chance of the Glow Plug Relay being damaged.

The Glow Plug Relay is not connected to the Starting Circuit until you are actually Cranking the Starter. When you do that there is a Purple Wire that either goes to a Terminal Block in front of your Battery (if you have that Terminal Block you can hook up the Remote Starter there) or is wired to the Solenoid on the Starter so that wen the Solenoid gets voltage the Glow Plut Regulator does also.

The one thing that the Glow Plug Regulator and the Starter circuit have in common all of lthe time is the Ignition Switch.

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84 300D, 82 Volvo 244Gl Diesel

I wish I was as smart as the other people on this site. I have been working on electrical problems on cars for over 50 years and still can't do it when I don't know what year the car is. The cars here in North Carolina change the electrical systems every year. Sometimes 2 times a year.
Oh well, I guess some have it and some don't.

Paul

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84 500 SEL (307,xxx miles)

Well Im fairly certain it isnt the NSS since a failing nss usually gives warning HOWEVER im not seeing any reverse lights on when the key is in the on position. I will check that later.

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1981 300SD 512k OM603

its the nss


I jumped the wires like diesel911 stated and the car cranks.


Thanks alot guys

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1981 300SD 512k OM603

Did that fix you window and turn signal issues?

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1981 300TD "The Green Lantern"
1980 300TD
1983 300D Euro "China Cat"

It does not have a designated ground point, look at the wiring diagram, you can see how the switches, switch the ground point around to cause the motor to go up or down. Look at the diagram below, your issue is most likely the ground point G102...I believe this ground point is near the shifter...

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Nothing like diagnosing a problem that was solved three years ago.

Not that it is of any consequence, but what's the point of insisting that the ground point is not "designated?" What does that mean?

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When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl.

That's odd....don't ask me how I posted on a 2011 thread...

Most motor's run in only one direction and thus they have designated negative lead and a positive lead....motors that run either direction were never equipped with a specific neg and pos lead...

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