Air conditioner compressor when using defrost

Volt · Oct 5, 2019

I would like to be able to not activate the air conditioner compressor when using the defrost. Has anyone figured out a way to manually control the activation of the air conditioner compressor when using the defrost? Does anyone know if the air conditioner compressor is or is not activated when the blend knob is set in between floor and defrost?

OMGitsme · Oct 5, 2019

Push the AC button and it shuts off. You get faster/better defrost with it on.

TacoMamba35 · Oct 5, 2019

Pretty much every make and model uses the air conditioning compressor intermittently for defrost. It acts as a dehumidifier. You're better off letting it operate as designed.

hiPSI · Oct 5, 2019

Volt[OP] initial post: ↑

I would like to be able to not activate the air conditioner compressor when using the defrost. Has anyone figured out a way to manually control the activation of the air conditioner compressor when using the defrost? Does anyone know if the air conditioner compressor is or is not activated when the blend knob is set in between floor and defrost?
Click to expand...

Any time you do anything HVAC the compressor is turned on. The reason? Two fold..
1. So the compressor seals won't dry out in the winter months where it gets cold.
2. During defrost, the AC will pull moisture out of the air and speed up defrost.

Modern vehicles have a complex system. Much more than a compressor turning on and off when you want cold air.

Drainbung · Oct 5, 2019

hiPSI said: ↑

Any time you do anything HVAC the compressor is turned on. The reason? Two fold..
1. So the compressor seals won't dry out in the winter months where it gets cold.
2. During defrost, the AC will pull moisture out of the air and speed up defrost.

Modern vehicles have a complex system. Much more than a compressor turning on and off when you want cold air.
Click to expand...

WARPED5 · Oct 5, 2019

TacoMamba35 said: ↑

Pretty much every make and model uses the air conditioning compressor intermittently for defrost. It acts as a dehumidifier. You're better off letting it operate as designed.
Click to expand...

... and some folks don't realize that it's DRY that does the job, not so much warm air.

Good reply, BTW!

Black DOG Lila · Oct 5, 2019

MowTaco said: ↑

Hello TacomaWorld

I can't remember where I saw someone say this, but I didn't see a write up for it anywhere so I thought I'd make one.

When you turn your vent selector to defrost, the A/C compressor kicks on to de-humidify the air. Maybe there's no sense to it, but in my mind, it seems dumb to heat the air enough to where it won't freeze up the system, then cool it off with the compressor and de-humidify it, heat it back up again (if the temp control is on "red"), then blow it at your windshield. Kinda seems like wasted energy, and there's not much of that to spare (especially on my 4-banger )
So this mod allows warm or cold air to be blown at your windshield without the A/C running (basically just shoots it through the same vents but without de-humidifying it first) Keep in mind that it won't be as effective as with dry air, but it will still work. Also, you can easily still turn on the regular defrost setting if you want more effective defrosting.

It's super easy and takes maybe 10 minutes.

First, remove your fan selector knob from the climate control panel. It just pulls straight off if you give it a tug. Be somewhat careful, as there is a metal sleeve that fits inside the knob that holds it snug on the little metal post that controls the selector. It should stay in the knob, mine came out and was difficult to get back on in the right shape to fit.
Next, use a dremel or something similar (if nothing else, a file will work, but be very slow) grind off this little bump on the knob

It should be slightly recessed into the knob when you're done. you may need to remove it and take more off later if it doesn't work.

Next, pop the knob back into place. If it worked, you should be able to turn the knob past the defrost setting 1 "notch"

It may take a little extra effort if you didn't take quite enough off. If it won't go, grind more of the bump off.

That's it! Your truck will now blow air through the defrost vents without running the A/C. If you want to defrost with the A/C, just turn the knob back to defrost. Easy! I know... you were expecting something difficult with all that buildup... sorry?

I suppose this was maybe a little too detailed, but I know I sure appreciate it when write ups are painfully thorough... enough for me to even follow

Anyway, enjoy your increased MPG, power, and clear windshield
Click to expand...

Volt[OP] initial post: ↑

I would like to be able to not activate the air conditioner compressor when using the defrost. Has anyone figured out a way to manually control the activation of the air conditioner compressor when using the defrost? Does anyone know if the air conditioner compressor is or is not activated when the blend knob is set in between floor and defrost?
Click to expand...

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Air conditioner compressor when using defrost

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Volt [OP] Well-Known Member

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OMGitsme Well-Known Member

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TacoMamba35 Well-Known Member

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hiPSI Laminar Flow

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Drainbung Somedays you are the show....

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Air conditioner compressor when using defrost

#1 Volt [OP] Well-Known Member

#2 OMGitsme Well-Known Member

#3 TacoMamba35 Well-Known Member

#4 hiPSI Laminar Flow

#5 Drainbung Somedays you are the show....

#6 WARPED5 Well-Known Member

#7 Black DOG Lila Well-Known Member

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#1
Volt [OP] Well-Known Member

#2
OMGitsme Well-Known Member

#3
TacoMamba35 Well-Known Member

#4
hiPSI Laminar Flow

#5
Drainbung Somedays you are the show....

#6
WARPED5 Well-Known Member

#7
Black DOG Lila Well-Known Member

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