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Help! AC Failure

Hello Car Talk Community! I drive an 04 Acura MDX and I absolutely love it. Recently, my AC wouldn’t kick on until a few minutes into driving and I thought that was strange but I elected not worry too much. I turned my car on today and there was no AC at all. I drove a little bit and it didn’t kick on. We had put a new fan and motor in around this past January and it has worked great until now. I’d really appreciate help determining what to do next without spending so much that I have to sell an arm, leg and kidney. Here is my disclaimer/fear/other AC conundrum-before I was driving, I thought I’d try to see why my rear AC wouldn’t work, as it hasn’t for a couple years. I found a forum online explaining that Acura MDXs from early 2000s have an issue where the filter clogs up and the Power Transistor fails. I removed the filter, cleaned it and put it back hoping that would be enough (naturally, it wasn’t). I also opened the fuse box under the hood just to make sure it wasn’t a blown fuse haulting the Rear AC but it was not blown. I only mention the Rear AC details to provide context in case I somehow messed up my main AC. I know what’s wrong with the rear but the main has me wondering. If anyone has any thoughts or ideas regarding my main AC, please share! Thanks!

What motor are you talking about? Engine or a/c compressor?

Check fuses

Check if the a/c clutch engages when you turn on the a/c. Look in front of the a/c pulley and you see the clutch. Make sure it turns when the a/c is turned on.

If it does turn, you might be low on refrigerants or you might have a bad compressor

If it does not turn use a stick and give the clutch a little push. (keep your hands away from moving parts) If the clutch engages you very likely have a bad solenoid that engages the clutch when needed.

If the clutch does not turn when the a/c is on and you can’t get it to turn with a little push, check for low refrigerants, check low and high pressure sensor, make sure the fan(s) work

There are videos on youtube about how to check the pressure sensors, checking clutch and solenoid, measure pressure and so on.

There is more, but I think this is a decent start to isolate the area of the problem

The first things to check are

  • Is the AC compressor spinning or not?
  • Are the engine compartment fans spinning?

I doubt anything you did in checking so far has done any damage. To keep it that way, suggest you don’t try to add refrigerant yourself unless you are certain you know how to do it and have the necessary equipment. Modern AC systems require very little refrigerant, and are very sensitive to over-fills. What’s worse, the damage from a botched over-ill can prove expensive.

Hello! First and foremost, thank you for your replies. I am surely going to check everything that has been suggested. I have an update! Moments ago I turned on my car and turned on the AC just to see if it would work and it did! That means this problem is intermittent (for now). Any thoughts on the intermittent AC issue? And thank you for putting my worry to a rest about me somehow messing it up more :joy:

Parts of the AC system can freeze up and stop working. Then after the AC has been turned off for a while they defrost and it starts working again, temporarily at least. Usually whatever froze up will freeze up again.

Everything that was said above is still applicable.

Thank you all so much for the replies. I truly appreciate it and you all have helped me greatly. If anyone has any further comments feel free to share! Thanks!

A/C Compressor but interestingly enough we did throw a new engine in the car over spring break this year.