Defrost engages AC compressor

The 4 cyl. in my 2000 Taco was just fine, this one seems to have less grunt. If I knew it would take such a hit from turning on AC I would have gone for the 4.0

 

The 4cyl in my '98 Taco was a ballsy beast. I don't recall the AC ever making it break a sweat.

If I could only find that truck again.....

 

Not very well.

 

I don't remember loaning you my keys... so how would you know how well it worked? I never had a problem with them defrosting.

 

You live in the land of almost no humidity so it's not really an issue there. It's more the defog that needs the a/c, not the defrost. I need it a lot on cooler mornings here.

 

If there is any dust on the windshield, the humid air causes fog on the wind shield. Here in Pennsylvania, I can't imagine not having AC running to defrost. It just doesn't work.

 

While the defrost still worked in the older vehicles, they were MUCH less efficient. I can defrost my front windshield almost immediately now. My 70 Mustang didn't have that option, and I remember having to wait for the engine to warm up before I could defrost. Sure you don't NEED the compressor to run, but the efficiency is MUCH better with the compressor on. especially in areas where the humidity is higher.

 

The AC helps with defogging, but for actually defrosting frost off the window AC doesn't do anything. If I have frost on my windows it is already 32F outside and the air is not dried by the AC since the evaporator is only around 35F.

I set the heat to the center "floor" position and that gets plenty of hot air to the windshield which melts the frost just fine.

 

Lived in PA for the 1st 33 years of my life, (when I owned those non AC vehicles) so I know about humidity.

I KNOW that the AC helps dehumidify and defog, my point was cars did it for years without it, and it worked.

SO those who want to blow non dehumidified air on their windshield should have the ability to do it...

 

Just do the mod

 

I never said I wanted it...

 

Guess you never tried A/C to get rid of the moisture.

 

Buy a truck with out A/C

 

If I am not mistaken don't the ac have a low temp compressor shut off? I don't know where the set point is but I don't think it runs very much when it is below 30 or so. The mod seems like a good idea.

 

I did the AC / Defrost disconnect mod and my windows clear just fine. In fact, I don't notice any difference in the amount of time it takes them to clear. The temperature and velocity of the air blowing on the windshield has a much more significant effect on the rate of evaporation than the dehumidification from the AC unit. I think Toyota does this to keep the compressors in good shape as much as to help with clearing humidity from the windshield.
Anyway, just do the mod and if your window is a little more foggy than normal some days (for whatever reason) then just press the AC button and you will have the benifits of dehumidification when you want it (it still works).

 

Would a 1972 Blazer count?

 

If it's frost it's on the outside! Scrap it off A/C will not melt ice.

 

Yeah or maybe a 62 Pontiac.

 

The ac compressor only kicks on in the "blue" setting, once you hit a certain point on the temp knob the AC compressor kicks off. You can confirm this by the RPMs.

 

wut? The rest of us in cold weather get frost inside too.