Hi

I'm wanting to connect my Traffic-Pro GPS speed sensor (gal) wire direct to the speed sensor output wire from the Hall Effect sensor and have no idea where it is located on my 87 300D?

I don't have a W124 wiring diagram but I'd poke around the cruise control amplifier. The connection from the tranny sensor to the speedo is a coaxial cable or something that looks like that. I don't think it can be tapped. There must be a speed signal from the gauge cluster as well.

Sixto
95 S420
87 300SDL

Perhaps it is mounted in the gearbox. My speed sensor is there. (190E 2.3)

Hope it helps.
Sergio

Behind the instrument cluster on the speedo assembly you will find a small unusual looking device, it should be the 'Hall Effect" signal/sensor you seek.

Next question: While I know the instrument cluster can be pulled out from sitting behind the driver's seat, and I've never tried this on any MB, might it be accessed there or do I need to try from under the dash?

You can push the cluster assembly out from underneath, but if you want access to the sender than the cluster needs to be removed. Also, disconnect the speedo cable from the clip that secures it at the floor board, near the steering column.

I got it out.......there is a pod that is fastened to the backside of the speedo and it has one green/yellow wire plugged into this pod, or whatever it is, also there is a double wire inside a insulated black cover or tube, also plugged into this pod. Are these what I'm looking for and if so, which might be the one I should tap????

The 2 wire unit is the the Hall unit.