Lotus AC switch wiring

[Wo2m]

2005 Federal Elise
S/n 44700

Can someone help me understand where to obtain this signal for ac switch? (what goes to ecu pin "B9") literally the last bit of wiring i have left. would greatly appreciate it.

[Hondata]

<t>With the Lotus the AC output is controlled by the multi function relay box. You either can use that output (sorry, I do not know which one) or change the AC button from momentary to a off/on switch and use that output wired via the pressure switch to ECU pin B9.</t>

[Wo2m]

Rgr, so the b9 is an input (12v?) So the ecu knows the compressor is on?

[Hondata]

B9 is an input that tells the ECU to switch on the AC compressor.