[ZeGermanHam]

Hi all. The kickdown solenoid plug on the new-to-me TH400 I recently installed was broken and needed to be replaced. I purchased a new solenoid that came with a 1-wire plug, which if I understand correctly, is the "early" style. My car's wiring is setup for a 1-wire solenoid, so I'm all good there. However, my new transmission was previously setup with two wires (see photo below with old solenoid & wiring still installed).

If my new solenoid is a 1-wire setup, do I need to use that second white wire for anything or can it be removed? I'm not familiar with TH400s, but it's my understanding that the white wire is just an emissions thing that cuts off vacuum advance in all but 3rd gear. In other words, not needed?

Thanks in advance.

[gto4ben]

Yes, the wire can be removed. It's connected to a TCS switch like you said.

[ZeGermanHam]

Perfect, thank you Ben.

[stevep]

That is a 1971-later transmission

[ZeGermanHam]

Yep, the donor car was this 1971 GTO.