On my 1990 300 SE the speedo does not work. After checking the transmission I found that it has a manual cable and very odd a magnetic pick up just tied up under the car that would look like a speedometer pickup. When pulling the cluster out found that the harness that ends up down at the transmission is plugged into the back of the speedo and the cable (if it is the cable) is just hanging behind the cluster. I bought the car used so I don't know if the cluster was changed or the transmission was changed. Not assuming anything however the transmission does not shift into overdrive, but I would assume the transmission is the original one in the car. According to one Mercedes repair shop they say it is a magnetic speedometer pickup and it is to fit into a hole on top of the trans. (no hole) According to another he said it is the cable. I bought a cluster from ebay that I can tell is from an 85 and older car (no SRS, ABS, Outside temp, Coolant Light etc.) (he described it for a newer vehicle the year range that I have). I am not sure of how that the one that I bought will work, there is an 8 pin plug on the back of the head and a metal post that is soldered to the back of the circuit board on the speedo. I am just curious if anyone would know which is correct?? I was expecting to receive a female type of speedo connection (where a square cable fits into) but I'm not sure if that is even made. I did not look at what I thought was the cable to see if it is like what most would see as a speedometer cable like older American cars. Thanks for any advice.