My AC only blows warm air despite everything appearing to be fine. I bought one of those easy-to-use AC recharge kits but the pressure looks okay, around 32-33psi. The compressor clutch engages and starts spinning when I turn the AC on.
Should I just replace the compressor? I only checked the pressure on the low-pressure AC line.
The high side pressure needs to be checked to see what’s going on.
I “appeared to be fine” when I had a stroke. Take the car to an A/C specialist for a professional diagnosis.
I appreciate the morbid analogy but I’ve done every repair on this car since the day I bought it. This is the Maintenance and Repair section btw, if I couldn’t do the work myself I would have taken it to a shop. Just wanted some possible ideas because I start taking stuff apart
A full set of gauges is a good investment if you DIY your AC. But, if you only have the one gauge, check the pressure with the AC off, then on. If the compressor is working, the low side pressure should drop when the compressor kicks on.
Unless you have a refrigerant recovery machine, a vacuum pump, a set of manifold gauges, an oil injection hand pump, and a refrigerant weight scale, this is simply beyond your capability. If you want to just throw parts at it, be my guest.
Thanks, I didn’t watch the pressure level when I turned the AC on but now that I think about I don’t remember it dropping at all
Am I wrong in assuming there a number of symptoms that can easily be checked before having to remove and install an entire system AC system? I’m not claiming to be an expert in AC systems, but if you know more than me at least be helpful, not borderline condescending.
OK this is where have the full set comes in handy. If the low side doesn’t drop, or drops only a little, you could have a bad compressor or the system could be clogged downstream. With a high side gauge, if it is a clog downstream, the high side will go very high. If it doesn’t go up much, that would be the compressor.
Youi might also have a problem with your blend door allowing heat into the ducts. Common issue with GM, in fact I’m about to install a new blend door actuator on my Chevy for this very reason.
If you don’t have a cabin air filter, you could have a build up of gunk on the evaporator core, had a Honda that this happened to. So many things to go wrong.
Edit: If you go tearing into the system, you should at least take it to a certified AC shop and have the refrigerant removed. That is the responsible thing to do instead of dumping it into the atmosphere. When you recharge the system, you will need to get a vacuum pump to pump all the air out of the system before you introduce new refirgerant. You can get a vacuum pump from Harbor Freight for under $100.
At the very least, you need a proper set of manifold gauges so you can see high side pressure as well as low side. Check those pressures with engine running at 1,800 rpm and blower on high. Also record the ambient air temp and the temp of the air coming out of the center vent. once you get all that, I’ll give you further advice.
I know, I was mostly looking for the easy to check things. I admit the scale of some of the repairs are out of scope. But I would at least like to try and figure out the issue before bringing it somewhere.
Thank you for the advice. As I said on the other comment I at least want to figure out the issue before I bring it somewhere, but I do admit the scale of some AC repairs are out of my scope
One more thing, just because you see the clutch engaging and the outside wheel spinning, it does not mean that the compressor is turning. The clutch could be bad. There is a way to tell but I don’t remember off hand but I have seen this happen. At least with this, you don’t have to mess with the gas.
By gas do you mean refrigerant?
Does the can have a gauge that reads (not likely not I’m guessing…) into the 100 PSI+ range? If so check the static pressure; which means both engine and A/C off along with a closed can tap. It should be in the 120ish range if it has a full charge. A100 or under means it needs a little help.
Wonderful reply! I love it!
Before connecting gauges, check the temperature of the suction line at the firewall with the system on, if it is cold you have a problem with the HVAC controls.