That is what I hear when I turn the key to start.
Is there a relay between the key and the starter selniod ?
I can start by turning on the key to the run position, do the glow, then use my jumper switch at the starter terminal on the pas.fender.
So the starter is ok.
Ramed the trani selector back and forth to see if the lock out was the problem, no help there. Is there an easy way to short across the lock out switch without getting under the car. At 81 that is no longer fun.

__________________
1984 300SD turbo 126
"My true love"

God made me an atheist and who am I to question His wisdom

Classic battery problem. If new(er) check cables at battery end first.

Please explain how a battery make clicking sounds. I've never heard of that before.

__________________
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

When you jumped the terminals on the fender, you bypassed the starter lockout .

It sounds like either the starter lockout switch or shifter linkage bushings. Hopefully it will be the bushings as they are very inexpensive and easy to replace.

If it is the shifter bushings, there will be no click. Nothing will happen; it will just be dead. Then you can wiggle the gear shift sometimes and it will start like new.

Maybe starter solenoid?

You're correct. Using my phone, I missed that in the title.

One of the intermittent starting problems I had was a loose chassis to engine ground strap. Sometimes it would click several times and then after trying several things to troubleshoot the problem, it would fire right up. It appeared to be a starter solenoid problem. Changed two starters out before finding the problem, with help from this forum.

Yeah but the part that was emitting the click click sound was not the ground strap, but rather the starter solenoid not getting sufficient current due to the bad ground strap?

__________________
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

Thanks for the info guys. The ground strap is OK because it will start fine
from the jumper on the fender junction. The click sound comes from a higher area. It sounds like a relay engaging. Thanks for ruling out the trani
lockout.

__________________
1984 300SD turbo 126
"My true love"

God made me an atheist and who am I to question His wisdom

No relay in the starter circuit. Key switch go right to starter solenoid.

__________________
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 a wiring diagram of the starter system. Easy to follow.
The problem is no power FROM the lock out sw.
There is power getting TO the lock out as the backup lights come on when
in reverse with the key on.
If the lock out switch is removed is it serviceable?
Are they easy to remove?
I have my jumper coming up under the hood and into the driver side window.
Works great. turn on the key, glo and press the button.
Hope it doesn't rain.

__________________
1984 300SD turbo 126
"My true love"

God made me an atheist and who am I to question His wisdom

might want to check for an alarm system installed on the car.

the sound may have been disabled, but the sensors are still active.

you might find it easily by pulling the driver's lower panel under the steering wheel. If you you find a box with harness going into it that you are unsure of, that might be it. Run the part number. Just yank the harness out if you find an alarm control box down there.

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I have the same problem with my 84 300TD. Some times it will start from the key, and some times I have to jump it on the box on the right fender. I also get a loud click when I turn the key and it does not start. I have noticed that it will start more reliably when cold then when hot.

In my case it is not the selector bushings, and I don't think it is the neutral safety switch. The fact that the car starts when jumped suggests it is not the starter either.

W.

But if it always starts when the fender terminals are bridged it can't be the battery or cables, right?

There's reasonable room to R&R the NSS in a 126. You might as well replace the shift rod bushings while the NSS is out. Make sure the NSS tab is in the same position as the old one or you'll need yet another replacement. Ask me how I know :/

Sixto
83 300SD

If there is no spring back to the key would that indicate a bad starter switch? Can the starter switch be purchased separately? Can the switch be tested with the instrument cluster removed?
The steering lock unit was replaced four years ago and I sure don't want to go through that.
Thanks again

__________________
1984 300SD turbo 126
"My true love"

God made me an atheist and who am I to question His wisdom