PeachParts Mercedes-Benz Forum - 1983 300d won't turn over

We got about 2 feet up snow here where I live...
My 1983 300d was running just fine beforehand.

I let the car sit for 2 days (no chains for the tires and its horrible in the snow).

Now when I try to start the car it won't turn over.
The dash lights come on, glowplug light comes on, then goes off (as it should), then I turn the key and nothing.
I've tried turning it over in neutral and nothing...as well as hoding the key on
and jiggling the shifter around.
The only sounds I hear is a faint "click" from behind the dash (near the stereo). I hear a small click under the hood when the key is in position 2.
When I try to start it I can hear a faint click under the hood as well (solenoid?).

When the headlights are on and I attempt to start the car there is no dimming at all and they look pretty bright.

I jumped the starter Directly to the battery via the black box on the right side fender and the motor turns over!.

Can it be the ignition switch?
Is there an ignition relay?
Can it be the Neutral safety switch?

What would be the best way to test any of those?

The problem has occured a couple of times in the past...
But it would only take a another turn of the key to get it going.

Edit:
In retrospect .... While I was driving home in the snow before I parked it...
I got stuck in the snow for a second.
I had to rock the car by putting it in drive then in reverse several times very quickly.
Because of that I'm suspecting the neutral safety switch.

Is there a sure fire way of testing it? such as bypassing it.
Where exactly is the neutral safety switch located?

Any help will be appreciated.
Thanks.