1996 Toyota Tacoma Compressor won't engage

Hi willspence,

The A/C magnetic clutch receives its power from the A/C Amplifier ( right side of Instrument Panel).

If the A/C switch is turning on, then you do not have a power supply issue and the most likely fault would be the amplifier or a broken connection. At the mplifier, check the Black/Yellow ( Pin # 9 ) for battery voltage. If voltage is available, the continuity between the amplifier and A/C compressor clutch is broken.

Otherwise you could have a faulty amplifier.

Thanks- no volts@ black/yellow (I have shematic), so I'll replace amp- $90, so I hope it works!

Keeping my fingers crossed. :)

Good luck and have a nice day.

Maybe you can try looking at the printed circuit board of the amplifier to see if you can find any abnormalities. Look out for corrosion,indicating bad capacitors( leaking) or cracked solders. Some circuit boards can be repaired by replacing some capacitors and/or resoldering. That would be a cheaper lternative.

Board looks OK- no burned areas or visible cold solder joints, and no burned smell anywhere, so double fingers crossed.

I found some additional info on testing the amplifier and have emailed it to you.

Hope it is useful and I am not too late.

Thanks so much for your help!!

The new A/C amplifier arrived…. still no go. : (

all the tests as described on the PDF you sent me test good, but it's a little confusing- first it says disconnect the battery ground, but some of the tests are looking for battery voltage, and the footnotes say to have the ignition on... so I tested those with batt. gnd. connected. (I did the continuity and resistance tests with gnd. disconnected)

What next?

The battery negative terminal is disconnected only when you need to remove the amplifier. When doing test, the terminal should be reconnected.

If all the test are confirmed to be correct, then it seems the PCM would be the cause. The PCM connections are for working the A/C amplifier as well.