Can the glow plug relay become partially defective, or is an all or none type of part?
I could not get my '82 300 TDT to start. I replaced the battery and the glow plugs and it was still starting hard. I noticed that if I counted to 15 after the glow plug light in the instrument panel went out before I try to start the engine starts normally.
It seems that either the relay is taking longer to get the plugs hot or that it is turning off the light before it should. I took the cover off the relay and watched the contacts, and they stay closed a lot longer than the light stays on. The light is staying on about a count of 7, and I add 15 to that, so I wait about a count of 22 before turning the engine over and it starts good then.
Should I replace the relay? And if I do, should I replace it with an OEM type or one of those Bosch ones that stay on three minutes? I just put in a set of Beru glow plugs.