1984 Mercedes Benz 300sd Speedometer Impulse Transmitter

WILHELM300SD

MEMBER
1984 MERCEDES BENZ 300SD

Electrical problem
1984 Mercedes Benz 300sd Two Wheel Drive Automatic 200K+ miles

When I spent months looking for an old Mercedes, I noticed that more then half mentioned that the speedometer didn't work. So now I have one thinking it was an easy fix. I spent three weeks discovering that it has a sensor not a cable. Now I have searched the internet for days for a "Speedometer Impulse Transmitter" along with every variation I could think of. No one has such a part. The only thing I have not done is walked into the dealership and asked them. Where can I get the sensor for a 1984 300SD and what's it really called?

Wilhelm

1 Reply

DR LOOT

MECHANIC
2,311 POSTS

ELECTRONIC SPEEDOMETER Remove screw and pull sender out of transmission tail housing. Turn ignition on. Place a large screwdriver blade across sender tip. Move blade quickly off and on sender. Speedometer needle should move slightly. If not, remove instrument cluster and unplug connector at back of cluster. Connect negative lead of voltmeter on pin 3 and positive lead on pin 5. Repeat test of sender. If voltage is indicated, speedometer is defective. If there is no voltage, replace sender and harness.