Automotive Air Conditioning Information Forum (Archives)

Harrist7 on Mon July 25, 2011 10:39 AM

Year: 2002
Make: Toyota
Model: Camry
Engine Size: 2.4L
Refrigerant Type: R-134
Ambient Temp: 85
Pressure Low: 30
Pressure High: 250
Country of Origin: United States

Last summer, this AC did just fine - but this summer when Texas temps hit 100 degrees, at an extended idle it began to blow out 80-90 degree air. Going down the road, it blows out 38 degree air and even gets to 35 degrees after the day's heat dies down a little.
I have tried to clean the condenser. The condenser fans comes on and runs full-time when the AC is on. Could this fan be running, but not running as fast as it should - how does one check that? I had a Mustang radiator fan that did that one time - man, that took a while to figure out.......
Last night, when it was cooler, I put a high-ouput floor fan on the condenser and the AC blew 58 degree air, but without the added fan, it would only blow 62 degree air.
The system holds R-134, there seems to be no leak.
What are the high/low pressures supposed to be on this Toyota? - I could find them no where on the Internet.

This engine does put out a lot of heat that may be straining the system air intake at idle. It sure seems to me that an improper condenser/fan motor may be the culprit.
Of course, I have no way here at home of weighing my coolant. I do believe I have it close enough to correct that that is not the issue - but, you know, I "played hooky" that day in "Air Conditioning School," ha.

Oh, yea, my pressure readings above (30 low - 250 high) are at 2,000 RPMs. At idle (about 750 RPMs,) the readings are: 45 (low) 225 (high.)

Help me, I can't always just keep driving.....my work entails me idling sometimes.

P.S., thanks in advance for any help you old-time knowlegeable "Grizzlies" can offer - without a site like this and y'all's willingness to help others that know less, A/C repair would still be: "Don't touch it - it will kill you!" Like a nuclear reactor or rocket surgery.

TRB on Mon July 25, 2011 10:49 PM

Pressures seem high at both idle and the higher RPM. Check fans & charge level. Be sure you have only the OEM spec of refrigerant in the system.

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JJM on Mon July 25, 2011 11:19 PM

Your fans are not moving fast enough at idle. The fans should kick on when the compressor engages, and when pressures gets higher, they should roar a little bit... of course not like the roar of a fan clutch engaging on an old big V-8, but you'll hear and notice it... even with the hood closed.

I forget the pressure at which high speed should kick in, but safe to say if you can get the pressure up to 300 PSI (partially cover the condenser) without the fan speed increasing, you've found the problem.

Problem is probably 1 of the 3 fan relays in the relay center under the hood (forget which one controls the highest speed), or the pressure switch located near the receiver dryer, which controls both compressor cycling and fans. Check the relays first, then focus on the pressure switch.

If the pressure switch does need to be replaced, the system needs to be discharged first.

Joe

Harrist7 on Tue July 26, 2011 9:33 AM

JJm,

Thanks a lot.
I had thought that the condenser fan may not be turning fast enough - and it surely does not "speed" up when pressures increase - I didn't know it was even supposed to increase speeds.
So, instead of first installing a new fan motor, I will check the relays like you said - should be even cheaper $$ than replacing the whole fan assembly.

Thanks again, you guys and this site are great!

JJM on Tue July 26, 2011 11:08 PM

You definitely don't want to replace the fans on a hunch at $193 each from the dealer! Not that the relays are a bargain at something like $66 and $41. The pressure switch is pricey at $121 too. Make sure you test the relays and switch 100% before replacing these pricey Toyota parts.

Let us know what you find out.

Joe

Harrist7 on Wed July 27, 2011 12:44 AM

JJM,

Yes, I will let y'all know how it all turns out.

I did order the three fan relay switches today online, and got them for pretty cheap - compared. One is much more expensive than the other two, so I suppose it is the special one that turns on the high-speed part of the condersor fan??

Thanks again.....