Help identify mystery plug

[slapnpop]

In the process of trying to track down a short, I'm exploring parts of my electrical system I've never seen before.

What's this plug go to?

Secondly... What resistance value should I read between ground and the side of this plug that goes down near the abyss of the firewall?

One last question.
What resitance value should I read between ground and the fused leg of the headlight circuit in the engine fuse box.

If anyone is actually willing to measure these two values on a working car, I would be eternally greatful.

 

[SHOtimer]

If i'm not mistaken that is an ABS sensor plug. One end should go down into the wheel well and end up at the sensor in the knuckle.

Doug