It has not been that cold 45 hi/ 30 low. I have been pluging in the heater and it has worked until this morning. Glow plug light comes on and off but when I turn the key just a click and nothing. The engine does not do anything. It is not the battery and when the temp rises, it cranks fine. Could it still be the glow plugs? Please keep it simple I am new at this I am doing the reserch to get my husband to work on it.

Ronda