Install the $39 adjustable fan controller per the C5 Tech section.

 

Dude, you got me on this one-HOWEVER, I stand by my statements, as they are true for the vast majority of cars with electric fans that are, say, 10 years old, or older. When the high side pressure is high enough, it will dis-engage the A/C clutch, apparently, on the newer cars with PCM's as sophisticated as the C5's come equipped with. But this also happened on these older autos, too, if they were equipped with what we used to call simply a "High side safety switch". On many vehicles, especially the ones from the 80's and 90's, as soon as the A/C is activated, at least one fan is also switched. I will admit you are correct on this one, and I have not had time to research it further in my service manual, as yet. However, I have no reason to believe that you are wrong here, and thank you for the free lesson. I am always open to getting and giving advice, which is why I love this forum and access it whenever I have time. My sincere apologies to the fellow I accused of being "totally incorrect", as it was me who was in the wrong. As far as the PCM increasing the idle speed when the compressor is engaged, I am sure you are also correct on this, also. Again, I have been around long enough to remember when the OEM's used a solenoid to "bump" the carb linkage on A/C equipped cars so the motor wouldn't die. And a different solenoid (Anti-dieseling) to ensure they DID die when the key was turned off. Thanks again for the lesson, and it goes to show just how crucial the correct PCM operation is to our cars. And how accurate the PCM is when compared to the "old days!!

 

grinder11,

Hey, I'm old enough to remember the days when car salesmen referred to a "stripped" model as "no stove, no harp" .... (heater deleted, AM radio deleted) ... fuhgedabout A/C ... only on the most high end cars .....

I love learning about the, to me, amazing technology in today's cars, and love passing on the information. There is more computing power in the PCM today than literrally tons of computer hardware in the 1960s and 1970s.

I knew you were right on how the fans worked on "older" cars, just wanted point out the Corvette is a different animal. This forum is a great place to pick up good (and sometimes bad .... ) info on these cars ....

 

Most cars have a high pressure cutoff switch at the compressor outlet incase of overpressure. There is also a blow off valve incase the system gets way too high. There is also a low pressure switch on the low side line in case the refrigerant is too low, or is sometimes also used as the "cold limit" shutoff to prevent icing of the evap or comp damage. In addition, there will be a high side line switch near the condensor or dryer if you have electric fans which activates the fans at a certain psi.

 

[QUOTE=BlackZ06;1562481424]grinder11,

Hey, I'm old enough to remember the days when car salesmen referred to a "stripped" model as "no stove, no harp" .... (heater deleted, AM radio deleted) ... fuhgedabout A/C ... only on the most high end cars .....

I love learning about the, to me, amazing technology in today's cars, and love passing on the information. There is more computing power in the PCM today than literrally tons of computer hardware in the 1960s and 1970s.

I knew you were right on how the fans worked on "older" cars, just wanted point out the Corvette is a different animal. This forum is a great place to pick up good (and sometimes bad .... ) info on these cars ....

[/QUOTE Uh, you referring to my "bad advice" on the dude who was "totally incorrect"?? Which would make me totally incorrect?? Which I was, because YOU were totally correct!!???: rofl: I agree again about a lot of "bad advice" out there. I have a huge pet peeve, which becomes more than just trivial if you are the poor guy who learns it the wrong way from an "expert", and it goes like this: I have seen more mistakes made in cam and valvetrain articles about duration in "camshaft"(!) degrees (Obviously, it should be CRANKSHAFT DEGREES!!). LSA is in camshaft degrees, NOT DURATION SPECS!! And this from one of the more respected nationally published Car Magazines. But, one little typo like that could totally screw up a novices' learning curve. Same thing with piston rings-I have heard guys who have said the numbers/markings always go up (Which is true in every situation I have personally encountered in nearly 40 years of experience). But some people have said the opposite-that they go down-which is USUALLYwrong-but who knows-maybe they read it in a car magazine-which is where a lot of us DO get an early education in auto mechanics 101. It took every bit of experience I have learned in my many years of experience to find the gremlin in my 2000 C5's 427 Darton motor. It was a combination of some early AFR 225's having had the valvespring installed height .100 TOO SHORT (1.675 instead of 1.775- Which Tony said was a rare mistake made on a very few early 225's), which made the valvesprings V-E-R-Y stiff and prematurely wore out my cam bearings(They made it only 30,000 miles). This increased the distance between the cam sensor and the cam sensor "ring" on the cam itself, as the bearings wore out. To exacerbate things, the cam ring itself was ground .040 undersize when the cam was manufactured NEW!!! It all worked for the aforementioned 30,000 miles-then as enough accumulated errors/wear piled up, it would start and run as good as new-for 10 minutes or 180 degrees coolant temperature, whichever came first-then throw a PO336 code-every time!!! It took about 3 grand in diagnosis time at W2W to determine the problem- and about 3 grand more in repairs due to the exhaust overheating(It was cherry red-melted the rubber between the 2 steel attachment points on the car and the pipes!). I was outta cash and had to find the problem myself-which I finally did last summer-with a lot of help from Kurt and Billy at W2W, who informed me they had NEVER seen this problem before on an LS1 or later LS motor. By the way-Kurt also informed me that he has on several occasions asked people "in the know" at GM for this sensor-to-cam ring clearance gap- and is STILL waiting for an answer!! Surely-someone out there MUST know the specs on this-in my case-CRUCIAL-dimension! GM moved the sensor to the timing cover on the LS2's-maybe it was happening on other vehicles, or was to ease servicing (Which I HIGHLY doubt)-who knows. This has been a good thread! !