2008 toyota camry Intermittent A/c issues
 

hello i'm new to this forums site, but have been turning wrenches professionally for many years and never had a problem like im having. this ac system has whooped my ass and im ready to get it whooped. I have a 2008 toyota camry that has the auto climate control. the a/c works intermittently. now here is the thing. when its above 85 degree out it doesnt like to work. now here is the list of symptoms along with times it works and what its doing when it is not working.
below 85 degree it works,
now if i turn the blower speed down it will go warm. so as long as its below 85 degree outside and the blower on high it works pretty much flawlessly. if it stops i just hit the ac button off and turn it right back on and it starts working again.
freon level is correct,
when ac is not working the clutch is engaged.high side builds but low side stays around 65 to 80 psi there for no cool air..
ive changed the control valve in the compressor and it helped the ac a little but still no ac when its pretty hot outside. again compressor is running you can hear it engage.
now i did replace the radiator and fan assembly, thats when all issues started. the new radiator was a little thicker than the factory radiator that was in it. im thinking maybe adding a pusher fan to the condensor to allow better cooling. any thoughs??
parts replaced
fan assembly
radiator
descant bag
a/c compressor control valve
expansion valve.
correct freon level
correct oil level
a/c amplifier (hvac control module)
ive checked the high pressure switch and it has correct ground and voltage going to and from it. any help/ideas wont be shot down. and yes the fans are kicking onto high speed to like they should. both fans pull like they should so neither are reversed causing one to push and one to pull. i know the fan speed control unit is working correctly as well.
im not trying to just throw parts at it like, a compressor because thats $500 for a new one with no for sure that its gonna fix it. im considering putting a pusher fan on the condensor to help lower the pressures. like i said my low side stays a little to high for the ac to work correctly. but say its 75 degree and at night the ac will freeze you out and work with no issues at all. any ideas, maybe someone here has had this issues or something similar. so please help!!!!

V6 wise, swapping the ac relay with the horn relay might work some odd magic.

swapped out relay. no change in symptoms. does the same thing it has been doing.

no change with swapping relay

A few thoughts.

The automatic climate system is complicated Toyota has a website where for a small fee one can access Toyota model factory service info for 2 days. Might consider accessing the service info. Toyota has very good service info!

https://techinfo.toyota.com/techInfo...a.com%3A443%2F

The automatic system has its own built in diagnostic system with code read out. Toyota uses their own proprietary scanner to activate the system which can display codes on the cars climate control digital panel. These codes are Toyota codes and perhaps a third party scanner HAVING the Toyota code software can access Toyota codes. Various brands of scanners such as Foxwell offer generic code readout and an option to buy the scanner with say Toyota, GM, Ford, etc loaded onto it. One can also add this software to some scanners after purchase.

One can also obtain Toyota TechStream software which Toyota uses for at low cost for use with a laptop or smart phone. Check the internet for vendors.

When you replaced the radiator and fan assy what did you remove, unplug, etc?

Toyota may have changed of the climate system electronic communication between sensors, modules, etc from analog to digital. The digital is more susceptible to bad connections. Temperature changes can effect connection quality if there is already a marginal connection.

Is the 85F temp is outside air temp or cabin temp? The automatic climate system has both outside and inside cabin air temp sensors.

Is the compressor not working at this 85F? The climate system no longer uses the old style heater coolant valve. Hot and cold air are blended to get the desired cabin temp. The result being a problem with the blend door system can cause warm air to enter the cabin.

The engine compartment would have a pretty constant temperature as in hot. If the outside air was 85F or 105F what was inside the compartment would most likely never know the difference. Thus might look for things outside the engine compartment such as temp sensors. The climate system may also have a solar sensor. Any issues withe exposure to light?

Finally if the system is subject to temp changes, might put up a few cans of freeze spray. This is a hand held can of chemical that when sprayed like paint spray can onto something will COOL it down. If a component is subject to issues based on temp then cooling it down may have it start to work again.

when replacing the fans and rad i just had to unhook the fan speed controller that is attached to the fans that the fans plug into. that's all for that. and also yes 85 outside temp. cabin temp with sun normally 110-120 degree F. and yes the compressor is still on and working at this temp just no cold air. and that's when the low side will rise to around 80psi. i've checked blend door function and they are good on that part. also checked solar sensor and its working correctly. i have hooked a scanner up to it and it is reading no codes for the ac system. i don't get any blinking ac light on the panel. and yes this is the duel temp system. i've already changed the ambient air temp sensor and adjusted parameters to show correct temp on dash. also this car has a cabin temp sensor and it is reading correct as well. i use to be able to spray the condenser with cold water and get the ac to work when it is really hot out which brigs me to maybe its not getting enough air through the condenser. the rad i put in was a little thicker than the factory one i took out, however that brings me to contradict what i said about air flow, if you go down the road even in the 85+ temp it still wont work.. and yes compressor never kicks off. i've checked the clutch for slipping and no visual signs of slipping. i know this is a complicated system but this thing has me stumped and im not about to throw a $500 compressor or even a condenser on it on the whim of it even working.

The outside air temp sensor is located at the bottom area of the radiator. Have you checked this out?

What are the codes?

What were the H/L A/C system gauge pressures for A/C off and on? Get a small thermometer and measure the dash air temp with A/C at max when AC is cooling.

If a 4 cylinder engine the A/C clutch may be internal to the compressor.

the outside ambient air temp sensor has been replaced. and when working duct temp is 41 degree holding. it is not throwing any codes. pressure readings ac off both high side and low side are correct. on 90 degree day will sit about 100-110 ac off. with ac on i am getting 35 low side and 150 high side when ac works. so according to my pressures everything is good. but when it acts up the high side is normal reading but low side does not want to go down it wants to stay around 80 psi causing a no cooling issue. when i start driving the ac will start to work but will randomly stop working again. compressor clutch is engaged the whole time the ac button is pressed/lit up. which brings me to possibly not enough air flow across the condenser to cool the freon like needed but why does it still not work at 85+ degree, and it doesn't always work going down the road. it will start blowing warm with clutch still engaged all i do is shut off the ac and turn it right back on and it will work again and blow cold. the evap temp sensor is reading correct as well. unit is not freezing up and the ac drain is clear. sun sensor is working as it should. again ive hooked a scanner to it reset the ac amplifier like it says to do in the repair manual but problem continues to continue. intermittent cooling issue. now at night when it is cooler out or if its a cool day there is times the ac will work flawlessly then other times it will cut out or not work at all and yes clutch is still engaged ive checked many times. my fans do kick onto high speed like they should you can hear them cycle with the pressures but we just get insufficient cooling with the low side at a to high of a pressue for cooling but high side is fine i have flushed the system no restictions. it acts as almost if the ac control valve is acting up but that is new as well. you can hear the load on the compressor change when the ac actually works. im not wondering if i may have a short in a wire somewhere under the dash or under the hood causing a low voltage issue. im working on getting wiring schematics for the complete ac system inside and outside. and will start testing more wires for resistance and voltages.

also is a 3,5L v6 with the clutch on the front of the compressor

Low = 21.3-35.5 psi High = 199.1-227.5 psi

Refrigerant weight 15.9 to 19.4 oz.

Did you check gauge pressures when spraying the condenser with water?