E30Mark wrote:There is a place to fit a warning lamp for when the engine temp hits the red... my old 318iS had the lamp fitted, but i never over heated the car to see if it worked!
Fit a spare lamp in this vacant position, and short out the wire that goes to the brown temp sender on the engine to earth, the temp needle to climb into the red with the ignition switched on, see if the lamp illuminates.
All E30s have the position for an overheat light behind the red part of the temp gauge, but the scale on every E30 I've seen doesn't have a coloured translucent bit for it to shine through. The connections from the lamp just lead to one of the connectors on the back of the cluster, so whatever works the light, it's seperate from the cluster.
Some markets have an overheat light in the overhead 'check' panel, and this is worked (I think) by a switch in one of the spare positions on the water outlet/thermostat elbow on six pots.
Since the iS (or any other 4 pot) didn't have 'check' panels, then I wonder if the position in the temp gauge was used on these?