Type 2, AC and 105+ degrees doesn't mix.

I know the fan will spin freely when the engine is cold in the morning. I will check it out when the engine is warm tomorrow.

 

I understand your heat/AC problem. I live in the 100 degree summers. I have two full size vans and a Taco. I put electric fans on the AC condenser on all three and it seems to help some.
Good Luck!

 

If you get it when a/c is blowing warm at idle, as you described, it should show/indicate that the fan is 'roaring' or pulling alot of air and essentially 'stops' if you kill the engine, showing the clutch is locked to pull max air thru.
Also check the large pipe running along the passenger side tire well (about 3/4 inch) and it should be cold gas returning to the compressor.
ALso check the compressor clutch; if it's cycling real fast (say 3-4 seconds off/on/off) or if there's no cycling (engaged constantly) it may mean the charge is low or the fan issue as mentioned.
It'd be best if you can show the dealer at 105 degrees what it's doing. Don't let them pull it into the shop and get it in a cool place. ALso you can make them show on a taco on the lot how this is 'normal'?
Per above i think there are enough posts saying they get cooling at these temps to show ur issue is legit.
Persistence.
Good Luck.

 

Not to thread jack here, but is there a "standard" temperature at which an A/C should be in a vehicle?

 

A rule of thumb is that the air temperature coming from the vents should be in the 40 to 50 degree range. 35 degrees is about as low as you should go less you freeze the system. There are some variables that will effect that range such as outside temp or if you are recirculating the air, humidity, type of refrigerant being used and so on, but normally if the temp is in that range all is fine. You can read more here.
http://www.waynesgarage.com/articles/aircondition.htm

 

I use to go to Phoenix every summer for a week of training - either July or August. Humidity there was often times in the single digit range and the AC performance was never quite right. When I got back to my subtropical climate, the AC performed much better. As mentioned in another thread, temps may be better once the vehicles is rolling down the highway and the condenser is receiving better air flow.

 

Well... here is the thing about the engine's relationship with air conditioning. The cooling requirements of the 2.7 are 2/3rd the cooling requirements of the 4.0. Why 2/3? Because it has 2/3rd the number of cylinders and 2/3rd the total displacement. Your engine isn't generating enough heat to cause the fan clutch to lock up hard, like a 4.0 in similar conditions would. The same fan is shared between the radiator and the air conditioner, and the fan is triggered by engine heat from the water pump. That means that because you have the more efficient engine, you lose out on the air conditioning.

Also a bit more about the fan. There are at least two, maybe three different fan clutches out there. One is pink for the tow package 4.0. Probably the tow package one will lock at a lower temperature than the regular one. This would benefit the air conditioner.


Now about the Yaris... front wheel drive with the engine across the bay. It has electric fans on the radiator/condenser rather than the mechanical fan like on the truck. That means that it doesn't actually have to get hot for the fan to come on.

 

Actually, it should cycle like that, particular in 100 degree+ heat at idle. The reason is because there is nothing actually cooling the condenser. You can't just keep pumping the hot refrigerant, because the pressure will be too high for the system to safely handle.

 

How do you add it to a bone dry system...hot wire the clutch?

 

sometimes it will go in enuf to start the clutch but if it don't yes just run a wire to the clutch or a jumper wire inn the pressure switch plug. I love the stuff it works great

 

The compressor does not need to be running to add refrigerant. The pressure in the can or bottle will push it in. You are adding it to the low pressure side even with the compressor running and that side has pressure on it and it goes in. The reason you want the system running is so you can read the gages and not over charge the system. On an empty system you turn it on at the beginning but it will not run until a certain amount of refrigerant goes into the system (around 25PSI) because of a low pressure switch. Once the system gets enough in it the switch will start the compressor.

 

Actually it should not be cycling on a properly designed and properly working system. If a system is cycling because there is not enough cooling across the condenser at idle then the system is not designed properly or it may have some blockage restricting the air flow even if the outside temperature is 100 plus degrees and the vehicle is idling. Here in Texas it gets really hot with outside temperature well above 100 degrees and none of my vehicles cycle at idle.

In this persons case if that is the problem then either the switch is faulty, something needs cleaned, or an added cooling fan needs to be added to the system. I doubt it is the latter because no one would buy a new car that pumps out hot air at idle in 100 plus degree heat.

 

I will try to make this understandable. The system has a low pressure cut of switch to protect the compressor from running when there is not enough refrigerant to circulate the oil to lubricate it. this switch is located in line on the suction or low pressure side of the compressor. when the compressor is running it is drawing refrigerant in from the evaporator to compress it and send it to the condenser to cool and turn to liquid. If there is not enough refrigerant in the system the low side pressure drops and the cut switch switches off. when the compressor stops the ambient pressure comes up because there is still some refrigerant in the system and the compressor starts up and the cycle starts over this is why the compressor is cycling on and off. Now to mechanical fan clutch it is controlled by the temperature of the air that strikes the by metal coil in front of it not the water temp It has a viscous clutch that allows for some slippage at moderate temp's but pretty much locks it up when the temp's rise and more cooling is needed. since the air is passing through the condenser and radiator it gets hot and should cause the fan clutch to lock up if the clutch is defective it wont lock and you will get reduced air flow through the cooling stack There is also a high pressure cut switch to protect the system from high pressure caused by over charge, plugged expansion valve or insufficient air flow over the evaporator. Hope this helps.

 

Here is an update: I picked up my neighbor and gave him a ride home yesterday and we sat my truck and chatted for a bit in the AC. All of a sudden my AC light switch started blinking and it started blowing hot air. Took it to the dealer this morning and it turns out my compressor is going bad. The tech said all the previous times I had been in the compressor was over looked and not tested. So I'm wondering if it has been the compressor all along and if it has then it must have been bad from the factory. Any case they ordered a new one and will call when the part comes in. Fingers cross this fixes all the problems with my AC.

 

I have sat in my truck on hot asphalt parking lots with outside temps at >100 degrees with humidity over 70% for over an hour many times. Temp gauge never rises, with AC blowing out ice cubes. Sorry to say, there could be something wrong with your truck. I just don't know. Maybe the high humidity does assist AC. Seems like there's always a puddle of condensation from AC under truck when I drive off. Good luck. Bad AC is tough to live with.