[PeteKz]

Yes, yes, and yes.

As you know, the yellow wire is the start circuit, which energizes the starter solenoid, thus it only has voltage when the key is in the START position. The yellow wire also provides voltage to the CSV and TTS. The red/back wire grounds the CSV through the TTS.

When the engine is cold, and you turn the key to START, the yellow circuit energizes the CSV and a heating element in the TTS. The CSV operates because the TTS is cold and connects the red/black circuit to ground.

When the key is in START, the CSV will not squirt fuel when the TTS is warm enough that it interrupts the ground circuit. This happens if the engine itself is warm, so the TTS is warm, OR when the TTS has been warmed by the internal heating element even if the engine is still cold. That prevents the CSV from continuing to squirt too much fuel and flooding the engine, if you continue cranking it after it won't start.

If you disconnect the yellow wire to the TTS (on a cold engine), the CSV will then continue squirting fuel as long as you have the key in START, and you may flood the engine, which may cause you to CONTINUE cranking the engine and further flooding it. Be aware of that if you are experimenting.