I believe I can help. TCS=transmission controlled spark. This was a 1970 Emissions idea that was really B.S., the whole idea was give the engine advanced timing (via vacuum advance to the distributor) when it was only really needed, therefore reducing exhaust emissions. I spent a lot of time figuring mine out on my 70 chevelle 307--call me Mr. TCS
, they're all the same:
The TCS relay is a small relay box that is riveted to the wiring gutter that runs under the hood close to the top of the cowl, you know the one that carries the wire with fuse to the a/c/heater blower.
The TCS solenoid (sol) mounts on the passenger side of the intake manifold by the distributor. It is matallic colored and has 3 nozzles. One goes to the carb base (vacuum)
one goes to the distributor vacuum advance nipple, one goes to the top of the carb (clean air, no vacuum).
A wire runs from your tranny to the relay.
The theory: (I feel like I'm a GM tech spokemans
When the car is in any gear but drive, the small switch that is in the side of the tranny is not activated (not grounded), when you put the car in drive ( i guess 3rd or 4th with a stick shift) the tranny fluid puts pressure on the switch activating it and grounding the circuit that goes to the relay, this causes another circuit to trip that sends 12 volts via the blue and black wire with flat plug to the solenoid on the manifold. So what's that do? It triggers it to let full vacuum from the carb to the vacuum advance on the distributor. The relay is there for "those darn freezing Nebraska winter morning start-ups" Just kidding
it is actually for cold starts when you need full advance for the distributer, What knows if it is cold out?
This is the Next part of your question!
The green wire that "splits" into two with a 90 degree plug angle goes to the twin-blade temperature sender on the passenger side of the block, this is what tells the relay that "hey it's cold out!" and turns on the solenoid even if the tranny is not in drive.
As for the tar paper covered green wire--this goes on the driver's side of the block, this is the TRUE temperature sender that tells you if something is wrong with your engine, i.e. makes the Hot light come on or guage move.
I sure hope this helps, are you confused yet, my fingers have writer's cramp!