While driving my 2002 Montero into Ridgecrest (CA) today my air conditioning decided to stop blowing cold air.

It started out blowing a bit of cool air, but didn't get to the desired setting.

Does anyone have some tips on where to start with a diagnosis?
I read through the shop manuel (on-line version), it says I need a "scan tool" (MUT-II) to complete the diagnosis.
Is there a way around using this to figure out what needs fixing?

Thanks in advance.

Set of A/C pressure gauges. You'll need to know the high side/low side.

Thanks pcc

It looks like the system needs to be charged.
Another thing to add to the list...

Check the fuses first. Our '02 CR-V recently stopped blowing cool air and I figured it needed a charge, so I took it in to my ace mechanic. He checked the system and found it fully charged but the compressor clutch wasn't engaging. Traced that to a blown fuse which controlled both the clutch and the auxiliary A/C fan. After putting a 'scope on the fan he determined that one of the commutators in the fan had shorted and apparently it had stopped with that commutator in contact and blown the fuse. Rotated the fan by hand, replaced the fuse and voila! Cold A/C again...

So rather than replace the fan I'm playing Russian Roulette to see how long before the fan stops in that position again <img src="/forums/images/graemlins/wink.gif" alt="" />

Eric W.

And those darn condensor fans aren't cheap either. You could make a cottage industry out of stripping them from every Montero in a junk yard you come across. I've replaced a couple of them so far.

John B.

Thanks for the tip about the fuse. I'll check it in the morning.
When your A/C stopped blowing cold air was it blowing air at all, or did the fan stop working entirely?
Mine was still blowing cool air, it just never gets to the selected cold setting.