AC compressor wire versus American Auto Wire

[K10-Kansas]

My engine came with an AC compressor with only one wire that I can find. The American Auto Wire ac/heater harness didn't come with directions. I called them and they said they don't have directions because there are too many different setups.

Also, the AAW wire has this weird bare metal jumper wire between the positive and negative wire?

Any guesses on how to connect this up?

[xylorex]

I believe you just need to connect the green wire to the pigtail coming off the ac compressor.

[RustyPile]

That "weird bare metal wire jumper" is a surge protector diode. A diode is an electrical version of a mechanical check valve -- it passes electrical current in only one direction. When an electrical coil is energized and/or de-energized, a damaging voltage surge or spike is produced.. In some cases, the spike can be several hundred volts.. Basically, that diode suppresses those spikes by bleeding off to ground..

A stock AC compressor has a two terminal connector and that plug will fit in only one position.. The diode isn't needed on the replacement compressor.. Simply clip off the plug, 2 terminal connector along with the diode. As stated by xylorex, connect the green (blue???) wire to the compressor's pigtail....

[RichardJ]

That diode is there to protect any electronic circuitry in the evaporator suitcase. If you're using any kind of aftermarket AC system that uses semi-conductor circuitry to open/close the doors and regulate the temperature, that voltage spike Rusty mentioned, from the clutch coil can fry it.
keep the diode and remember to observe the polarity. The white band end, stays on the clutch wire.

[K10-Kansas]

There was no connector to hook the black harness wire. I could have grounded the eyelet of course but the tech at American Autowire said to connect the green harness wire to the black compressor wire and clip the black harness wire and diode off.

[RustyPile]

Originally Posted by K10-Kansas

There was no connector to hook the black harness wire. I could have grounded the eyelet of course but the tech at American Autowire said to connect the green harness wire to the black compressor wire and clip the black harness wire and diode off.

The "Black harness wire" is a ground wire.. You can make it longer or shorter to reach the nearest mounting bolt for the compressor.. Most of the better aftermarket automotive electronic devices, including AC controls have built-in surge protection.. Your compressor clutch doesn't require an external ground, so you can clip the diode and ground wire off or, to be on the safe side, connect it to the nearest bolt on a grounded bracket.