Here is some good help from a guy on HT.com:


If A/C indicator light is not comming on then it's probably a wiring issue.
Most Honda/Acura A/C switches are 2PST, [2 poles on/off] and close a ground circuit, ground input comes from blower motor speed switch, [blower motor must be on for A/C to work] one pole supplies a ground for the indicator bulb, [LED] and the other supplies a ground to the A/C thermostat, which in turn supplies a ground, [when closed] to the A/C pressure pressure switch, which in turn supplies a ground the the A/C compressor clutch relay, or to the ECU/ECM that in turn sends a ground to the A/C compressor clutch relay that in turn supplies the compressor clutch with 12V+.

So find A/C compressor relay and make sure there is power, [12V+] on both the relays coil, [#85 or #86, hot when ign. switch on] and relays input, [#30 or #87, hot at all times] you can jump #30 and #87 to see if compressor clutch engages, if so, supply a ground to relays coil, [395 or #86, opposite of hot side obviously] to see if relay works, you can even supply a ground to the pressure switch plug, [load side] to see if that will engage the compressor to narrow down where the problem may be, but with the indicator light not comming on makes me think the problem is at the A/C switch or wiring going to it.

You did turn on the blower when testing the A/C, right? 94