What is that one wire?

[jhax]

Well for wiring purposes which one is which if there is a dedication?

[bajacalal]

This is where the glow plug temperature sensor is if you were wondering.



Yes, the oil pressure sensors are different, the one which goes on the oil filter housing operates at a higher pressure, and the are electrical opposites, the one on the head is a simple switch which closes to ground with no oil pressure, turning the LED on. They are marked with the pressure in bar somewhere on the sensor. 1 bar = 14.5 psi.

[jhax]

usdieseltoCE2engine by jhax32789, on Flickr

[jhax]

HAHA!!! SON! BBCode without the

[Toby]

I think you will find that they are both pretty high and the head might be a tad lower when hot and low RPM. 

The one on the head is about 6 psi the one on the OF housing is about 24-28 psi.

If you pitch the relay and bridge the terminals between the light and the head OP sensor it functions just like a regular oil light.