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.
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.
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.
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.
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.
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.