Relay and amplification help needed!

[Agent13]

Ok guys this is a little difficult to explain...

I have a 1990 Corvette that originally had a 350 TPI engine in it. I swapped that engine out for a LS3 from a 2010 Corvette...

My only problem is that I can't get the A/C compressor clutch to switch on.

Originally the A/C clutch was activated by the original engine's ECM which has been removed from the car.

What I have is the "A/C Request" wire (Circled in dark red in the diagram) that supplies 4.950 volts and 0.001 amps when the A/C is off and no voltage when the A/C is on. I tried using a 5VDC SPDT relay but the A/C request wire obviously won't trigger it due to the low current. I need to use that relay to ground the wire (Circled in bright green) that triggers the A/C clutch relay when grounded. The wire circled in green is 12 volts and 0.250 amps.

Is there any way to amplify the request wire just enough so it triggers the relay?

Does anyone have any other suggestions? Thank you!!!!

 

[dustin02rsx]

maybe a transistor?

i could be wrong but why not use another relay and a toggle switch to trigger the a/c relay and just bypass that wire all together?

edit: i may have suggested what you said you already tried. :doh:

so everything in that dashed box on your schematic was part of the ecm which is no longer in the car correct?