BigRed,

The GP relay does time the GP, but not as you said.

The GP are timed to stay on about 45 seconds all the time on a 300SD unless interrrupted by turning the key switch to the start position. The timing of the GP dash light is proportional to the temperature, but when it goes out, the GP are still energized ~45 seconds .

So its best just to wait longer before trying to start the engine than to start the GP cycle again and again.

If engine doesn't start, its also better to crank for short periods of time and then start the GP/start cycle again since the GP are turned off and start to cool as soon as the starter is energized .

P E H