Run AC with a toggle switch?

[letitsnow]

A couple years ago, I put a new motor in my '99 k2500. When doing that I removed the AC pump, condensor, all lines, and wiring connectors etc.. I have been using the truck this way and all is well, but I am now wondering about adding back AC...

Can I put a new compressor, condensor, lines on and run it off of a toggle switch?

I want control over when this makes cold air. I don't want anything turning the compressor off if I give it full throttle, don't want the fan being turned on automatically, don't want the compressor to run when I turn the defrost on. I want control over when that compressor makes cold air.

Any idea if that would work?

I am not asking for opinions on whether my idea is the right path, I am only asking if the system will function this way.

Thanks.

 

[PlayingWithTBI]

Can I put a new compressor, condensor, lines on and run it off of a toggle switch?

The least I would do is wire a low pressure cycling switch as well as a high pressure shutoff switch in series from the toggle switch to the clutch coil so you don't burn it up.

 

[Dropped88]

Agree with playingwithtbi. On adding pressure switches to protect the compressor and the system from exploding over a extreme over pressure.

 

[letitsnow]

The least I would do is wire a low pressure cycling switch as well as a high pressure shutoff switch in series from the toggle switch to the clutch coil so you don't burn it up.

Thanks. I will look into that if I do this. I can't decide as it sure is a nice, simple set up with no AC stuff in the way!

 

[mykytiuk]

A couple years ago, I put a new motor in my '99 k2500. When doing that I removed the AC pump, condensor, all lines, and wiring connectors etc.. I have been using the truck this way and all is well, but I am now wondering about adding back AC...

Can I put a new compressor, condensor, lines on and run it off of a toggle switch?

I want control over when this makes cold air. I don't want anything turning the compressor off if I give it full throttle, don't want the fan being turned on automatically, don't want the compressor to run when I turn the defrost on. I want control over when that compressor makes cold air.

Any idea if that would work?

I am not asking for opinions on whether my idea is the right path, I am only asking if the system will function this way.

Thanks.

Yea you can! I did this myself with an old Ford Escort “town car” that all the dash switches quit working. I used two toggles, one to directly power the compressor (I think I went to the relay) and one to power the electric fan when moving slow or stopped. At the first sign of not blowing as good you need to turn it off for a bit for it to defrost.

 

[Mr Eric]

Thanks. I will look into that if I do this. I can't decide as it sure is a nice, simple set up with no AC stuff in the way!

I have set it up that way before. One word of advice: use a reply, between the compressor and toggle switch. It makes the switch longer lasting, as the electrical isn't full amperage at the switch.

Just remember that as the compressor is running full time, it will begin to freeze up the evaporator, you will need to manually cycle it off to show it to warm up for a deice cycle. Forget and it will freeze up completely and no air.

 

[Insert Quarter]

Could A/C thermostat solve the freezing problem?

https://www.summitracing.com/parts/fss-35845?rrec=true

 

[PlayingWithTBI]

You need both pressure switches installed or, when you start it back up a few minutes after shutting it off when hot, your pressure will spike high enough to blow up the compressor, blow the high pressure switch out, or blow out seals - ask me how I know. Or, if you lose your charge due to a leak, you'll burn up the compressor for lack of oil circulation, if you don't have the low pressure cycling switch installed.

You won't have to worry about it freezing either since your pressure will go up as it starts to freeze so, your high pressure shutoff switch with start cycling it automatically. Given everything else is correct - proper charge, air flow, etc.

 

[PlayingWithTBI]

Could A/C thermostat solve the freezing problem?

https://www.summitracing.com/parts/fss-35845?rrec=true

No, all it does is turn the compressor on/off based on cabin air temps. If the evaporator freezes, the thermostat will think it's too warm inside and keep the compressor on.

Also, in their schematic, they show "Optional" Compressor Safety Switch. IMHO you NEED these low and high switches for safety!

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[letitsnow]

The least I would do is wire a low pressure cycling switch as well as a high pressure shutoff switch in series from the toggle switch to the clutch coil so you don't burn it up.

If I do this, below is what I plan to order. It looks like the oem low pressure switch shuts off at 22 psi. I haven't found the high pressure switch yet - I assume this would go on a port on the back of the compressor?

What do you think?

Thanks

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