Remote starter diagram
 

For anyone interested, this is how I installed my remote starter. 1982 300SD

The remote starter is actually designed for a generator. It is completely manual in operation. Three buttons on the remote (ABC) A was wired into ignition circuit. B is a momentary output that was wired into the start circuit. As long as I am pressing B the car cranks over. C is for future use. There are no brake or tach inputs. The unit is shut back off by pressing A again. I am able to leave my car running, locked, keys in my pocket. Great for idle cool down.

All wiring was done at the back of the ignition switch, soldered in place. Solid pink is battery power, purple works the starter, pink with black tracer works the cluster and glow plugs. Two relays were wired in because of the large wire gauge off the back of the switch. An over boost protection valve was used to control the vacuum shutdown signal to the IP. The entire unit, including the relays and valve all fit behind the cluster.

The connector is removed from the ignition switch by turning to position I and pulling back on the connector.

The unit has been installed as pictured and works very well.