Hey all, I'm new to the site, but have owned Toyotas for quite a while. This is my 2nd Runner (used to have a nice 97) ... anyway, just got this 95 a couple weeks ago and the AC is acting a bit strangely. For the most part, it works great and blows ice cubes, but whenever the temp gauge crosses over the halfway point, the AC cuts out. It still blows air, but not cold. I'm not that great with AC systems, so any ideas on where to look, how to troubleshoot, causes, etc. would be greatly appreciated. Many thanks in advance...
Paul

PS -- AC *does* come back on when temp gauge goes down. Highway driving is fine, stop/go gets hot and kills AC ... drive highway again and AC will kick back in.

 

I am new to this site also. I was looking for an answer to exactly the same problem on my 95 4runner. I just replaced my: thermostat, hoses, water pump, timing belt, and assorted belts and guess what the things still overheats enough to cause the a/c to kick on and off as you describe. Luckily,those other things needed to be done anyway. So... I looked more closely at the a/c issue and the slight overheating problem. I noticed firstly that the electric cooling fan for my a/c was missing the wires to the electic motor . The wires rotted away, I guess. So I said "Ah ha!" I replaced the fan motor. (Bythe way...The motor costs $170.00 at the dealer so I made a trip to the u-pullit junk yard up the way and found no 4runners ,but about 1/8 of all foriegn cars use this same motor on their a/c units. I just had to unscrew the old blade and housing from the motor and install it into the toyota housing and it even had the same plug and everything. I think the motor came off a mid 90's nissan sentra but many cars had this same triangular motor.) So I put the motor in and... the problem continued. Then I thought it might be the timing, so i got a timing gun...but it still overheated and it was timed correctly. I then looked into the fan shroud housing. the fan shroud has a two inch wide plastic strip that runs around the bottom of the fan shroud and up the sides. I assume it helps to channel air out of the radiator, I had left it off during my repairs. SoI made sure it was back in place. But it still overheated. I then looked into the fan clutch. The fan has a temp sensitive fluid filled fan clutch. When the engine is cool it spins some, then as it warms up the fluid and thermo coupling squeeze together somehow and the fan will generate more wind until it cools down again and the fluid coupling relaxes and slows the fan and the wind. I read that you can test it by spinning it when the engine was fully hot and it should be hard to move. "Hard to move" is a relative term. Here is what I noticed. The fan was most difficult to spin freely when it was cold. As it became very hot it would almost freely spin,(this is the opposite as it is supposed to) meaning I could spin it with my hand and it would travel around 1 1/2 revolutions or more depending on the time I tested it. It seem to free wheel the most when my car was overheating the most- during those intermediate speed times 20 -40 mph or so. Hmmm? I went to the local parts shop and got a new fan clutch and intalled it in an hour or so. Getting it out of the box i could tell this was going to help. The fan would not free spin cold and as I heated it with the car heater it tightened up more and more. So in it went. You just need to pull the fan shroud and the clutch has four nuts. I did not need to loosen the pulley it was on because the screws are in the pulley and keep things pretty well lined up. So I traded out the fan blade reinstalled and...
So far it looks good but it was evening and not as hot as it was, but it had been acting up the night before and now it has seemed better. I was excited to finally make some headway so I just had to tell someone. Hope this can help you track down your prob. I'll tell you how the next few days go before you run off to buy a fan clutch.
Tom

 

Tom -- Wow, I really hope that fixes it. PLEASE let me know when you get a determination on it. I really don't know where else to go after that unless there's some kind of sensor or something along that line needing replaced. BTW -- I saw the same thing about the little fan as well -- doesn't look like mine is running either. Glad to know there are plenty out there -- I'll start scrounging around as I'm sure it must be there for a rason anyway - LOL! Hopefully the clutch is the trick though ... thanks!
-Paul

 

For proper A/C a lot of air has to be drawn through the condensor and rad.
Does your A/C work at highway speeds?

 

Yes, at highway speed the AC blows cold as ice ... in city traffic, the cold air cuts out (air still blows, just not cold). If I go highway again, the AC kicks back in ...

 

When you switch on the A/C the electic fan is supposed to run while the compressor is engaged to draw air through the condensor. If it's cold on the highway I'd suspect the fan isn't working.

 

The a/c blows cold 100% of the time. In heavy traffic, up hills and on hot days! The fan clutch was shot. Once I replaced that fan clutch it was smooth cooling. The a/c never kicks off anymore. Sorry I waited so long to get back. I have been waiting for a good few hot days here in Chicago and I have been leary to claim success to soon. I have been duped before.
I hope this helps and that your fan clutch is the culprit also. Now I can tow my trailer and have AC. Isn't life great....
Later Tom

 

PS I have noticed that my heat guage never makes it to the half way point now, where before it would climb to just at or a little above the half way point and then the a/c would kick off.
Just an observation.
I agree with Marc to check the electric fan. If the electric fan runs OK and your radiator looks to be good, I 'd try the fan clutch.
Tom

 

I was not sure of this myslef a month ago but... and maybe this can help others trying to follow this thread:
There are two fans invloved here the electric a/c fan is on the outside of the radiator and can be seen through the grill.
and...
The second fan is the one with the clutch on the inside of the engine compartment that is driven by the pulley system. The clutch is the big silver thing with the fins that is screwed to the fan blades.

By the way..It is a pain in the ass to get to that electric fan. You have to take off the grill and the two turnsignal lights first. The pain is the little clips they seem to be designed for installation only. I was thinking it would never go back on. I think it is on but just half the clips are holding now. There were too many clips in there anyway. I hope.

On the electric fan check that it can spin freely and activate it with the a/c before reassembling. I bent the the little metal shroud while installing it and the blades were resting on the radiator. Then I had to disassemble it again. Hmm. Maybe that's why I thought that was such a pain in the ass. I did it twice...

I'm done
Tom

 

hey guys

would that be a possible cure for my a/c that used to blow cold and now is just mildly cool? i ran the inside cab fan at full and it barely cooled the inside. it used to blow nice and cold on the lower settings up to yesterday. there is lots of water coming out the drain pipe and the cab is somewhat cooler but not the way it should be. normally, it would only take a few minutes to cool down the cab, now running the fan on high just takes the edge off. i have a trip planned for later this week and would like to be able to use the a/c. any suggestion or comments would be appreciated.

lee

 

If there's lots of water coming out of the drain pipe that should indicate that the A/C is in fact working. You could check if your heater control is stuck open some how which would allow hot air to mix with the cold air. Is your compressor cycling and how often does it cycle?

 

i just went out and checked the hearter controls, i had dusted the dash earlier today but didnt check to see if any controls were moved. none were, they all move nice and smooth and i can hear the flaps opening and closing while moving the controls. ill check the cycle in the am, how often should it cycle? would the clutch/fan assy be a possible trouble spot? let me know what you think and ill post tomorrow with the cycle times.

thanks,

lee

 

That seems to have been the ticket -- it's working! I've driven around for a few days now and it's run like a charm! I would've never guessed that was it ... but I replaced the clutch and it's running great! I checked my electric (condenser) fan as well and it seems to be running fine. Is that fan supposed to run all the time when the AC is on? Or does it kick on periodically whenever it needs to?

Thanks so much for the help!
-Paul