glowplugs and more not working in the morning
 

1980 300TD, pencil style plugs, When I try to start the car in the morning, None of the lights on the dash come on that usually come one (battery, brake, wait to start), the head lights and blinkers do not work, but the door buzzer does work. The car will not start. I tested the glow plugs with an ohm meter, and They all read the propoer resistance. There is twleve volts at both ends of the glow plug fuse, (at all times even when the car is off). Later on in the day after the sun has been shining for a while, the car does not exhibit any of the same symptoms. And all of the signals/lights work, as well as all of the glow plugs, and the car will start.
I figure there is a short somewhere, that is being affected by the amount of humidity that accumulates at night, but do not have a manual, and do not know what connections/relays to check. thanks!~

Would you be a little more specific on "won't start"?

Is it cranking slow or sometimes not even turning over? (Batt. Grounds Starter and more)

Or is it cranking fast but just won't seem to light? (Glow Plugs, Fuel)

sorry about that, it turns over fine, just does not fire. I suspect it (the problem) is also affecting the fuel shut off, since almost everything else is affected. . (it has one right? like a vw diesel?...) What color wire carrys juice to everything that the key powers when in the "ON" position? I bet that will elad me to my problem. thanks

The fuel shut-off is vacuum driven, if the engine is spinning normally, the starting problem is most likely the glow plugs not getting any power. You can verify if the glow plugs are getting power (11V) even if the indicator light isn't working.

To try to answer your question, my Haynes manual has a diagram for your car. It shows a red/black wire from the ignition switch (contact 15, which is energized in position 2) to the fuse box. This feeds fuses #8, 10, 12, 14, and d. This circuit also sends an input to the glow plug relay and the indicator lights (from upstream of these fuses). I would check to see if those fuses are energized when the key is in position 2 (run). If not, the glow plug relay is probably not sending power to the glow plugs (even if the power feed to the 85A fuse is energized). You can also hear the GP relay click on and off if it's working. Sounds like you may have a problem with the ignition switch or the associated wiring.

Hmmm.......
 

The thing that puzzles me is the fact that you don't have your normal warning light test. This might indicate a grounding problem. Does this model have a separate grounding wire at the glow plug relay? If you turn your switch to "glow" and wait, do you hear the glow plug relay cycle? (It is a heavy duty relay so it is very audible.)

But with the other strange symptoms, such as no blinkers, etc. the ignition switch itself is sounding very suspect.