This thread is all about FJ60/FJ62 A/C amplifiers. You know, that little black box that mounts on the evaporator case behind the glove box. There are plenty of other threads concerning A/C amps and I thought about adding to those, but in the end decided that the information here breaks enough new ground that it deserves a dedicated thread. There are details here about the A/C amps for the FJ60 (p/n 88650-60020) and the FJ62 (p/n 88650-90A03) . Both are fairly similar and designed to perform three functions: 1) prevent the compressor from engaging during engine start-up or at low idle 2) increase idle speed when the compressor is engaged 3) disable the compressor if the evaporator coils get too cold (i.e., near/at freezing) The major difference between the boards is how #1 is implemented. The FJ60 board has rpm sense circuitry that is driven by a signal from the igniter that inhibits the A/C clutch relay from closing at low rpm, while the FJ62 uses a signal from the ignition switch that disables the relay when the starter is engaged and for a short time thereafter.