Not the worst problem to have in August. I noticed my fresh air being very cold. The AC button is shut off, the green light is not illuminated. The green light will toggle on and off when I press the button. Regardless of the state of the AC button the air is cold and I can visually see the compressor cycling on and off. Could it be a fuse or relay? Would the button light still toggle if it was? Can anyone point me in the right direction? Thanks!

 

By chance is your defroster on ?? that tends to cycle the AC clutch more then when the air condition is on..



you can still cycle the AC switch on and off with the defroster on.

What happens when the blower is shut off does it still blow cold air?

More often when the AC system has a glitch it quits working.

If your defroster is not on quite possible your AC amplifier has some issues or the AC amplifier thinks the AC is On or the Defroster is on

 

The front defroster is what I use most of the time. I don't really like air blowing in my face. However I've never noticed cold air coming out like it is now in the past 20 years of owning it. I did read that some cars do automatically turn on the AC to remove moisture when the front defroster is turned on, but I don't believe the 4Runner was doing this in 2000. It is something I would do manually when needed.

Toggling the AC switch seems to have no effect. As far as turning off the blower do you mean the little draft of air that still comes through without the blower? I pretty much have the blower on but at a low setting most of the time. Rarely do I shut it all the way off.

 

My 2000 runs the A/C when in the defrost mode until outside temps are just below freezing.

 

With the blower motor off the AC clutch should drop out.

If it does not then best guess is a AC amplifier issue.

 

Any progress with this??

I am curious if you figured it out.

 

I hopped into the EWD book and interesting the section is called "Automatic Air Conditioning". Here's the description of the AC system, kind of sounds like it does operate in a somewhat automatic mode, but it doesn't actually say the situations where the auto on would activate.



There's also a section for manual AC, here's the description from that section.



Just guessing, but I suspect the "auto ac" is probably push button style AC controls while the manual is the old school manual slider/turn dial type.

Anyway, as stated above, with the blower motor completely off, you shouldn't see the AC run at all, if it does, there's clearly an issue and I'd agree with checking the ac amplifier first. Another possible idea could be the relay stuck on (if you have auto ac, manual doesn't have a relay).