Hi guys,
Sorry to butt in, but this seems like the best spot to insert a related question. I've been struggling with lousy starting in my 83 300d for about a month now, and it's now fully unable to start without a jump from another car. Accompanying this is a loud whine that sounds like it's coming from the glow plug relay, and no movement at all from the starter. Has anyone come across something like this before? (It appears there is some sort of parasitic draw on the battery that easily drains it overnight) Could either or both of these be caused by a defective Neutral safety switch? or is this a number of separate problems working together?

I've tested the NSS/ignition bypass in front of the battery with a jumper wire, which will crank, albeit with insufficient power from the tired battery. This seems to suggest a faulty NSS, non?

poor starting/inability to start, and relay whine.

would low voltage at the glow plug relay (about 7-8 volts at the main fuse) from the drained battery cause these symptoms? or am I thinking about this the wrong way? I should mention the battery is under a month old. What could cause that kind of voltage drop?

The glowplugs themselves, as well as the associated wiring, appear to be fine. I tested them using Diesel Giant's walk-through

Sorry about idea vomit. Your help is greatly appreciated