The Ultimate A/C Thread For Pigs! (Air Conditioning) (1 Viewer)

[PabloCruise]

So, I've read, I think, every thread here. Can anyone explain to me how the idling stabilizer amplifier works. From the wiring diagram, I see that it's connected to the coil. When the signal is sent that the compressor is running does the engine rpm actually increase to compensate. If so how does it do that. Is there some sort of solenoid that presses the throttle on the carb to increase the rpm? Please excuse my ignorance if this is a stupid question. I ask this because I'm trying to use an OEM a/c system and I'm not sure what all I'm missing part wise to make it all work.

This is an important question. I *believe* there is an idle-up solenoid that kicks up the RPM @ idle when the AC compressor is powered. But I do not have very specific knowledge.
My situation is that using the 3FE w/ a computer, I need to figure out how to wire my system so the dash controls can interact w/ a 3FE compressor, as well as signal the computer to adjust the IAC as is appropriate.

 

[abqcruiser]

Pablo, from what further reading that I have found, the early systems did not have an idle up feature. If I understand this right, the idle stabilizer amplifier has an adjustment on it that senses, from the coil, how high or low the rpm's are. It acts as a switch and won't kick on the compressor until the idle is at a certain rpm. I could have this completely wrong, but there is no solenoid back to the carburetor to increase the rpm's. The fj60's however do have them. I would follow Delancy's build, He is using an OEM a/c set up with the 3fe. Unless he is carbureted, he will be dealing with the same computer issues.

 

[PabloCruise]

Pablo, from what further reading that I have found, the early systems did not have an idle up feature. If I understand this right, the idle stabilizer amplifier has an adjustment on it that senses, from the coil, how high or low the rpm's are. It acts as a switch and won't kick on the compressor until the idle is at a certain rpm. I could have this completely wrong, but there is no solenoid back to the carburetor to increase the rpm's. The fj60's however do have them. I would follow Delancy's build, He is using an OEM a/c set up with the 3fe. Unless he is carbureted, he will be dealing with the same computer issues.

Very cool. I'll try to find Chris' posts on the topics and link here...

 

[PabloCruise]

Before I lose track of this thread again - here is a sweet thread on how to rebuild the 3FE AC compressor: FJ62 A/C overhaul with Denso 10P15C compressor rebuild

 

[PabloCruise]

Some info on 3FE AC compressors: 3FE Air Conditioner (AC) Compressor ID Help Needed Please!

 

[PabloCruise]

Pablo, from what further reading that I have found, the early systems did not have an idle up feature. If I understand this right, the idle stabilizer amplifier has an adjustment on it that senses, from the coil, how high or low the rpm's are. It acts as a switch and won't kick on the compressor until the idle is at a certain rpm. I could have this completely wrong, but there is no solenoid back to the carburetor to increase the rpm's. The fj60's however do have them. I would follow Delancy's build, He is using an OEM a/c set up with the 3fe. Unless he is carbureted, he will be dealing with the same computer issues.

I believe @Delancy did run a carb on his 3F.

 

[PabloCruise]

So, I've read, I think, every thread here. Can anyone explain to me how the idling stabilizer amplifier works. From the wiring diagram, I see that it's connected to the coil. When the signal is sent that the compressor is running does the engine rpm actually increase to compensate. If so how does it do that. Is there some sort of solenoid that presses the throttle on the carb to increase the rpm? Please excuse my ignorance if this is a stupid question. I ask this because I'm trying to use an OEM a/c system and I'm not sure what all I'm missing part wise to make it all work.

Did you get AC working w/ your 2FE?

 

[PabloCruise]

Pablo, from what further reading that I have found, the early systems did not have an idle up feature. If I understand this right, the idle stabilizer amplifier has an adjustment on it that senses, from the coil, how high or low the rpm's are. It acts as a switch and won't kick on the compressor until the idle is at a certain rpm. I could have this completely wrong, but there is no solenoid back to the carburetor to increase the rpm's. The fj60's however do have them. I would follow Delancy's build, He is using an OEM a/c set up with the 3fe. Unless he is carbureted, he will be dealing with the same computer issues.

Had to go all the way back to 2014 to find his build!

First Time Pig "Build"

Need to dig to find where he was setting up his AC.

Wonder why he doesn't come around here any more?

 

[PabloCruise]

Had to go all the way back to 2014 to find his build!

First Time Pig "Build"

Need to dig to find where he was setting up his AC.

Wonder why he doesn't come around here any more?

Unless I am missing something, not much tech detail on how he set things up. Oh well...

First Time Pig "Build"

 

[abqcruiser]

Hey TJ,

I really didn't have to change anything on the a/c. It ran great the whole time at PP18. I still don't have an idle up feature on the engine and I'm not sure if the rheostat on the idle stabilizer amplifier even works. All I know is it never bogged down the engine at a stop light to cause it to shut down. I've been meaning to have a chat with @cruiserbrett on if I need to wire in the a/c cutoff that's coming out of the ecu. You're engine might still have the bits for idling up when the a/c kicks in. If so, I'd like to see some pics of that part.

 

[PabloCruise]

Hey TJ,

I really didn't have to change anything on the a/c. It ran great the whole time at PP18. I still don't have an idle up feature on the engine and I'm not sure if the rheostat on the idle stabilizer amplifier even works. All I know is it never bogged down the engine at a stop light to cause it to shut down. I've been meaning to have a chat with @cruiserbrett on if I need to wire in the a/c cutoff that's coming out of the ecu. You're engine might still have the bits for idling up when the a/c kicks in. If so, I'd like to see some pics of that part.

Great to know, thank you.
I will pull out my 3FE ECU and see if I can figure out how to integrate that with the ‘74 AC controller...

 

[cheetahbait]

Can anyone identify these AC units? Who makes them? I scavenged thes images online and was trying to find which units to buy.

 

[cruiserbrett]

Good luck. That style isn’t factory, and isn’t one I have seen with any regularity... so they’ll be hard to find, until you find one...

Not to be a wise ass, but I’d look at various options folks have used in this forum. And they’ll be new with better performance...

Only thing worth retrofitting used is OEM.

 

[cruiserbrett]

Great to know, thank you.
I will pull out my 3FE ECU and see if I can figure out how to integrate that with the ‘74 AC controller...

I have a solution for integrating factory a/c to an efi motor; to get rid of the idle speed cutoff function.

Perfect for a piggie with a diesel, or an efi motor that can control idle speed when a/c is on.

It works without any coil input(rpm) but still allows stock thermistor and temp dial to set temp.

More info to follow. Going to build a few for sale, so I will need to get a star. Will include controller box and a small wiring adapter, with or without a wire to integrate to ecu “a/c on signal”

Definitely works with 73 and later systems, but I am going to create a slightly different harness adapter for the 70-73 style.

If you come up with a stock underdash unit, without wiring or controller I can also get you functional with this and a new harness.

 

[PabloCruise]

I have a solution for integrating factory a/c to an efi motor; to get rid of the idle speed cutoff function.

Perfect for a piggie with a diesel, or an efi motor that can control idle speed when a/c is on.

It works without any coil input(rpm) but still allows stock thermistor and temp dial to set temp.

More info to follow. Going to build a few for sale, so I will need to get a star. Will include controller box and a small wiring adapter, with or without a wire to integrate to ecu “a/c on signal”

Definitely works with 73 and later systems, but I am going to create a slightly different harness adapter for the 70-73 style.

If you come up with a stock underdash unit, without wiring or controller I can also get you functional with this and a new harness.

Sign me up brother! This sounds like exactly what I need!

 

[abqcruiser]

So will this act as an idle-up as well? With my current stock set up, I have no way to increase the idle, unless I press the gas pedal, when the compressor kicks on. It really bogs down the motor at a stop light, so I'm constantly shutting the a/c system off until I get rolling again. I'd be interested in one too if it will solve those issues.

 

[cruiserbrett]

It does not do anything with idle up.

It is simply the “amplifier” that controls the compressor clutch and does so without any rpm input required. It does this using the stock control knob and thermistor.

Not sure why you idle speed control valve isn’t working, but that should keep the engine from lugging way down when the compressor kicks in...

 

[PabloCruise]

So will this act as an idle-up as well? With my current stock set up, I have no way to increase the idle, unless I press the gas pedal, when the compressor kicks on. It really bogs down the motor at a stop light, so I'm constantly shutting the a/c system off until I get rolling again. I'd be interested in one too if it will solve those issues.

Are you using the 3FE ECU?

 

[abqcruiser]

It does not do anything with idle up.

It is simply the “amplifier” that controls the compressor clutch and does so without any rpm input required. It does this using the stock control knob and thermistor.

Not sure why you idle speed control valve isn’t working, but that should keep the engine from lugging way down when the compressor kicks in...

So far my amplifier seems to be working fine. It's been so long since I looked at my wiring. From memory, there's one wire from the ecu to connect in to the a/c wiring. Maybe I have that wired incorrectly?
It's one of those little inconveniences that I've been meaning to go back to try and remedy. I'd still be interested in your amplifier. Mine won't last for ever.

Pablo,

Yes, I am using the 3fe ecu.

 

[cruiserbrett]

The idle speed control valve should open up a bit under the compressor load and at least try to keep the engine idling around 650rpm.

FJ62 and FJ80s didn’t cut the a/c off when at idle. The ecu has the ISCV compensate for the load and attempt to keep the idle speed at 650rpm.

I don’t think your ISCV is working properly...

The A/c on signal to ecu from amplifier just raises the desired idle speed to make the a/c system more efficient and blow colder. Compressor spins faster, and fan moves more air over condenser.