Im trying to figure out what this little thing is under the key switch in my 1983 300SD. Its about the size of a credit card slot

Its obviously missing its little faceplate. this pic with th Green LED lit was the vehicle running in park.



The one where the little incandescent bulb is lit was at a stop light in gear with my foot on the brakes.

maybe some kind of trailer brake controller?

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I was thinking either a brake controller or a wig wag for the brake lights. Do you have a trailer hitch? Do your brake lights flash when you press the pedal while in Drive?

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-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250

Perhaps an aftermarket brake activated park interlock?

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Thanks,
Mark in NC

"Spark plugs?...We don't need no stinking spark plugs!"
1985 300SD "Der Silberne Schlitten" 420,000 mi


Wish these were diesel:
2003 Ford Club Wagon 130,000 mi

No trailer hitch to speak of, I should have said the Incandescent light doesn't come on every time i press the brake pedal. but it seems the brake has to be pressed for it to come on.

Brake lights do not blink when the are applied, the function normally.

I don't know much about this car other than it sat in a barn for the last 5 years before i rescued it. The elderly man that owned it is suffering from dementia and had lost the ignition key and i had to have the column removed and the lock disassembled and replaced.

Just going over all the little things to get it road ready and functional.


I don't think its a shift interlock either as i can shift the trans regardless of key position.

Follow the wires, what does it attach to?

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Cheers!
Scott McPhee

1987 300D

Heres another view.



ITs just got two wires coming out of it, One being a black ground that goes over to the parking brake area and is under a bolt and the other a red wire that is scotch tapped into a Pink or salmon colored wire under the steering column. The red wire is fused before it gets to the little black box thing.

... just taking the registration to any mercedes dealership would get you a matching key. no dis-assembly required.

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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 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Couple of reasons behind why that didnt happen, One the Previous owners family Tried to get a key made at the dealer. After two attempts at non working keys they figured out that the ignition had been changed at one point.

Second i haven't had a chance to transfer the title into my name yet And will most likely wait until i get the car back in full operating condition before i do so. When that does happen i will get the factory lock tumbler to match the door locks.

If this means you have separate door keys from the ignition... and assuming you still want to mess with it... you can get a new ignition tumbler that would presumably match the doors. Same process as going to the dealer to get a key.

My first thought with your mystery box was trailer brake controller. Can't think of anything else that would activate with the brake lights.

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08 R320 CDI current

Past
95 E420
87 300D Turbo 5spd
90 300TE
83 300SD
85 300TD
92 400E
85 190D

some had factory radar detectors?

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77' 300D, "Cartman" SOLD @ 150K (didn't know what I had)
83' 300SD, "The Superdon" 325k+ @ 28mpg
95 E320 wagon, "Millennium Falcon" 231k+ @ 24 Mpg
95 E300D, "Sherley" 308k @ 33.69 Mpg, currently anticipating a head
99 Suzuki Intruder "Trudy" @ 45 mpg

I will eventually get the Correct ignition tumbler from the dealer in due time.

They didnt have any keys that fit anything when i picked it up from them. just a car and the title. I had to winch it out of the garage onto my trailer around a corner. thank fully the wheels were pointed strait ahead. With a huge bottle of dawn soap and a snatch block for a change of direction off a rather large tree she came out the garage and onto the trailer.


When i get the thing registered in my name i will have to drive it down to the dealer and see if they can cut me a key to fit the door locks and then get the ignition to match. Right now i just have an Ignition key.

It might be a radar detector but its only got two wires coming out of it.

What does the reddish pink colored wire under the dash where its tapped into go to?

I would think that the factory radar detector wouldn't use a scotch tap?