2010 Tundra 5.7 A/C Help -- Compressor Clicks on and off at Idle

I have been troubleshooting warm a/c while at idle. Any load above 1,000 RPM and it blows cold whether the truck is moving or not. Some things I have checked after searching this and other sites:

- Verified the fan spins nicely.
- If I push on the fan with the engine off it does not spin freely.
- I cleaned the condenser up.
- I replaced the belt and tensioner since it was whining right before this A/C problem start.

I also just bought an A/C Pro can. When I hooked up the gauge it went straight to Red, which AC Pro says do not add any coolant. If I keep the gauge on and rev to 1,000 RPM, it goes into the green zone. I have not added any coolant.

I zeroed in on the compressor.. sometimes the clutch portion is just sitting there still at idle without blowing cold air. Other times it goes on and off, when it is spins it blows cold air. I captured a video.



Is this just a bad compressor or clutch? Anything else I should be checking before I replace that?

I have done a lot of searching so hopefully I didn't miss something obvious and someone can help me out.

Thank you!

 

It's probably low on refrigerant, in spite of what you think you see on the gauge. The clutch SHOULD cycle off and on. In the first place what RPM are you referring to when you say 10K? 10K is 10,000 RPM, and I know you're not revving that high. You're about to waste a whole bunch of money trying to do this yourself. It's probably not a problem with either the clutch or the compressor or any other component. At least take it to a reputable A/C shop and let them check it out.

 

You are right, certainly not 10k. That should have been 1k. Anything over 1,000 RPMs and it blows cold and shows the right pressure.

 

The gauge is going to show red if the comp isn’t running once it’s running the pressure should drop
It does sound like your a tad low on Freon I would try putting just a bit in and see what it does If it has to much Freon and the pressure is to high the comp. won’t run at all no matter what engine speed is , that’s what the pressure switch is for

 

Like they said low on refrigerant.

 

have you looked at the electrical connection? try putting a volt meter on the wires to see if it is turning off electrically or if it is mechanical. you should get a 12v reading on and off if not then it’s mechanical. it could be a bad low/ high pressure switch also pull the connectors and jump the wires if the compressor still cycles then you know it’s not the pressure switches. don’t leave wire jumpers in long you don’t want to burn up compressor.

 

Checked cabin air filter?
Blower speed on high while idling?

Compressor clutch cycles on low pressure Switch
Don’t put any refrigerant in until u are sure that’s the problem

 

At the very least, rent the correct manifold gauges from Autozone/Oreilly's. They are free to rent. Then look up the high / low pressures at ambient temp and see where you sit.

 

Like others have said, that's a sign of low refrigerant, so you probably have a leak somewhere, take it to a shop and let them diagnose it for you.

 

I will have to do some research on the best way to jump the wires. Do I need to go from the compressor to the battery or just jump a relay or something else?

I will try this Saturday.

Yes, blower maxed out.
Cabin air filter was recently replaced.

 

Closing the loop for future readers.

I went to the shop talked through all of this and they agreed it could be as simple as low freon. While it might be something else, might as well try that. Same conclusions you all drew.

I went ahead and added freon knowing that my next stop might be paid for help. Adding the freon took care of it so far.

The truck has a 170k miles on it, so not too surprising. Low pressure side now holds. I have still not tested the high side. I will update this post if anything changes...