AC compressor for onboard air

[Junkie]

Has anyone set up the AC compressor to act as an air compressor? I never use my AC and have had the condenser removed for at least 6 months. I'd like to be able to air my tires up and maybe even use air tools every now and then. I know that I'd need a filter and then something to oil the air before the compressor, and then a manifold with fittings and a pressure regulator after the compressor (and maybe an coil separator).

I'd consider running it to a tank, I know that a lot of AC compressors run on the order of 300psi so either I'd regulate it before the tank or use a high pressure tank (intended for SCUBA or welding or whatever, and capable of much higher pressure).

How would I control the clutch on the compressor? I wouldn't want it running all the time of course. I suppose a manual switch would be fine, but don't know which wires on the compressor do what.

If it matters I have a 99 Legacy Outback, which uses a compressor designed for R134a.

Thanks for any help.

 

[NachaLuva]

Cant help with any advice but if you can do it would be a great idea!

 

[Dedman]

In terms of controlling the clutch just use the ac switch in the car or relocate that switch to where you want it.

 

[taza]

Done it at work a few times as we specialise in automotive electrical.
Works really well and pumps super fast. You dont need a xonstant supply of oil to it. Just put oil in the suction side every month or so.
The low side will be your intake side and high side is the output. You could use the factory wiring. You would need to include the pressure switch which I'd highly recommend.

Feel free to ask any questions.
I considered this but in our hot climate im not willing to give up my air con.

 

[Junkie]

Where is the pressure switch? Is it on the compressor itself or is it the AC related wiring closer to the firewall?

What do you like using for an air tank? I'd like to run a tank up near the max pressure that the compressor can output, which I would guess is 300psi or so. That way I can have the same volume of air without taking up as much space.

 

[Fazed]

Old fire extinguishers have been used before and are usually small enough for most ppl's needs. Not sure if they go up to 300 PSI and if that is the max the A/C compressor can output then I'm pretty sure you may wear out the compressor a lot sooner.

 

[El_Freddo]

The wiring is simple - use the wire that goes to the clutch on the compressor - trace this as I know on my EJ it meets with two wires from the high pressure switch mounted on top of the compressor unit. Run power and add a switch inline to the compressor clutch and you can turn it on and off at will.

I'd have some sort of high pressure cut off in the wiring too - I don't think the unit on the compressor is suitable for this setup. But I'm 99% sure you can get a pressure switch that's adjustable to trigger the compressor pump on and off. You should be able to tap into the idle up circuit that'll help with the load on the engine...

It's something that I would like to do, but run a secondary compressor as I'm using my AC now

I've also thought about a fire extinguisher as the air tank - my biggest problem would be working out where to mount it... Some day

Cheers

Bennie