Wiring help with HO Alternator Please!!

[CTScott]

Originally Posted by Yaris Lighter

Thank you so for your reply Scott! I shall do just that!
But I just want to double check.
Will I then have a problem with the ECM and A/C ECU not receiving that signal or will it not really effect anything worth worrying about?

That is a good question. The service manual does not explain if lacking that signal will cause an issue. I would say to connect it up and then try the A/C. I suspect that it will still work fine. It is probably more of an issue for "cold weather package" Yaris, which have the PTC heater. That may be what the AC ECU prevents from powering, unless it sees the alternator output signal.