This AM it was 9 degress F (-12.7 C, 260 K) at elevation 7200 ft (2200 m)
and I have noticed that when I preheat with 3 block heaters the engine gets
so warm the glow plugs do not come on and the engine is hard to start.
When I let it sit a few the plugs come on and Motorious fires right up.
Is there a way to adjust the "turn off" temp for the relay?

http://home.earthlink.net/~gnarlodious/Vanagon.html
Vanagon Diesel '83