The glow plug relay on parallel systems doesn't connect to an external [to the relay] engine temp sensor. Does it measure resistance in the plugs to determine engine temperature? Does it have an internal temp sensor?

Thanks,
Sixto
91 300SE
81 300SD

Sixto:

There is a thermistor in the relay.

This makes the glowplugs come on with a hot engine, too -- helps with hot starts and with emissions on startup.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Even with new glow plugs, I can't get the system to glow when the engine's cold. It glows for a moment (and enough of a moment) when the engine's warm. I guess the cheap way out (new glow plugs) didn't do it for me.

Thanks,
Sixto
91 300SE
81 300SD