I need some help. I'm new at diesels. My daughter has a 1981 240 D. The glow plug light has stopped coming on. I put a test light to the glow plugs and there is no power until the key is turned to the start position. I checked the glow plug controler and it shows power to the red wire in the run mode. The ground test good. The fuse is good and the controler has power.
The glow plugs, at least some are working because the car still start even when very cold.
Any ideas would be helpful.
Thank You

Mark Theofanides