A/C Compressor question

Failure rate is pretty low + they didn't sell that many in America = very little free DIY info in public.

Probably the best thing you could do is rent the official Repair Manual from Toyota. It's not expensive and it is the best step-by-step info anyone ever wrote for the job.

Details on this link.

 

Also, figure out why the old one died. The two most common ways seem to be hitting road debris that hits the compressor itself, since it's pretty low on the front of the engine, and the other is loss of refrigerant.

Because the car has automatic climate control, it will try to compensate for low refrigerant level by working the compressor extra hard, without telling you anything is wrong. Eventually it just does too much and thrashes itself to death.

So... you may have more than just a compressor to deal with. Be suspicious and careful when you are leak-testing.

 

Sure thing! also, you should be aware of car-part.com. It's a database of parts in junkyards. Not the easiest-to-use website, but it is worth it because of the savings.

With such a low failure rate, it means there's lots of perfectly good compressors available from crashed cars. You can save a bundle that way.

Good luck!

 

A corroded low voltage control connector is the most common way that Prius AC compressors fail other than mechanical issues. Improper control signals could also lead to mechanical failure.

The connector is so situated that it collects water and corroded.

I filled mine with dielectric silicone grease to prevent this many years ago.

Corroded connectors can't be repaired. A new compressor is the only option.

 

If I remember right, an algorithm got added into late-ish model Prii where you can straight-up ask Techstream if the refrigerant charge is correct. The car already has a variable-speed compressor, a high-side pressure sensor, and evap and ambient temperature sensors, so it was just a matter of adding some ECU code to use those features to judge the refrigerant charge. Saves having to open the system for the more invasive ways of judging that.

My 2010 hasn't got that feature, but something in the back of my mind thinks I might have been reading about a c when I first learned of it.

 

Neat! maybe I need to get a techstream running again. my windozer broke, so I'm down to the Macs and raspberry pi's for now. Would be kind of cool to do that as a periodic test.

 

Leave the orange one alone. You can unplug the low-voltage one. Seal the connectors (both on the compressor and on the plug you took out) really well, say by cutting thumbs off some rubber gloves and then sealing those over the connections with vinyl or silicone tape and/or plasti dip. You'll be able to remove those cleanly when the time comes. Secure the unplugged wire connector so it doesn't flop around.

The low-voltage connector on the compressor faces up and is great for collecting water if not sealed, and that will mean needing a new compressor even if you don't already.

 

I would leave the orange high voltage cable connected. Otherwise you can get a high voltage leakage code pretty quick. Some get it in the amount of time they take to do a head gasket.

The Toyota online TIS system does have procedures for mechanical replacement of the compressor. That part is easy. They will tell you to properly recover the refrigerant, measure the refrigerant oil in the old compressor, test for burn out, typically change the txv, ideally change the dryer, pressure test with nitrogen, pull a 500 micron vacuum, do a standing vacuum test to spec, add new refrigerant oil based on how much was removed, add refrigerant without sealer or oil and finally measure superheat and subcool.

The kicker is it requires training and expensive tools to do these things. If you are sure it is the compressor, you might buy it from an online Toyota dealer to save markup.

 

What country are you in?