Temp sender unit -- which is which?

[MarcMyWord]

I have a '70 pickup with the original 250 cid and 3-speed manual trans. I recently had to take the head off and have since forgotten where a few of the wires attach.

My head has two temp sending units. One is on the water inlet housing, and the other is about mid-way along the head on the drivers side. If my research is correct, the one unit is for the idiot light (my truck does not have gages), and the other is part of the TCS loop. Problem is, I can't remember which is which.

Also, more out of curiosity sake rather than any needed functionality, does anyone have schematics (vacuum and electrical) of the TCS emmisions system? As with most trucks this age, mine has long been bypassed but all the components are still in-pace.

Thanks,

Marc (MarcMyWord@aol.com)