300Tdi glow plug timer-Temperature dependent?

[roverdevin]

Hi folks,

I am sorting out the glow plug circuits, which the previous owner said was likely never used. I have a couple questions:

The glow plugs appear to be shorted or grounded at the contacts...is this a sign of faulty plugs, or am I doing something wrong? Is there a way to check the plugs?

The timer has been wired to use the now unnecessary "Check Engine" light as a glow plug light. When I key the ignition, the glow plug main circuit gives 12v for about 8 seconds. The warning light, however, only gets a few seconds power.

Is the glow plug timer temperature dependent?--i.e. is it shutting the light off early as it doesn't need much glow time?

Thanks for any help!

Sincerely,

Devin B