This page describes C34 owners' solenoid for glow plugs upgrade project. The installation of a solenoid to the glow plug circuit will reduce the time to hold the key or push button that powers the glow plugs preheating the engine before starting.
Most solenoids have two tabs with holes for mounting.
These tabs must be grounded for the solenoid to work. Fabricate a plate or find close to matching mounting bolts on the rear of the engine. This means that it is hanging upside down over the rear of the engine. Two bolts were used to mount it, using one of the bolts to connect the ground wire that is wired to the ground on the engine. This is the wire that goes up the wire harness to the glow plug switch.