I attach the 1999 wiring diagram, which for the greater part should cover your Canadian 1998. See pages 2 and 4. On page 4 in particular, left side, middle, there is an "A/C Amplifier," which many call the computer for the A/C system. On the lower left, the engine computer ties into the A/C system a bit.As the title says I would like to add A/C to my 98 convertible i just picked up. I searched the forum and have found out that apparently US rav4's all come standard with A/C so im guessing mine may be from canada because the speedo reads in kmh. So has no cooling a/c components. No compressor, condenser, lines or even an a/c button. I have a doner car with working a/c but was wondering if there is a separate a/c ecu or is it all controlled through the main ecu?