97 Lumina - Air Condition Troubleshoot & Repair

I am not an expert but can manage to do most mechanical things if I have guidance or access to How. My lumina has 73k miles and is not blowing cold air, it has dual control driver and passenger, 3.1L engine. On turning the A/C on I don't hear any clicks, Max Cool. ofcourse I will check this again to make sure. From driver side it blows neither hot nor cold air, some times cold if it is a cold day, but on the passenger side I definitely can feel little bit hot air. From reading through this forum I guess it can be Actuator on passenger side. I also tried recharging with a can from Walmart which also came with a guage. As soon as I connected the guage reading was in the Alert range. So I didn't recharge any thinking the problem is somewhere else. I could be wrong. It was a hot day.

Any help in troubleshooting (step by step) will be helpful and appreciated. I tried bringing it to PEP Boys but they said it is a 2 day wait to get to repair. Being in storm (Katrina) affected region, can't find many repair technicians, we can forget about the charges ($$$).

The low side reading will be very high if the compressor is not operating. And if the system is low, the compressor will not run until it begins to sense pressure in the low pressure switch, then it will engage.

Is the compressor engaging (clutch turning with pulley, or clutch stationary)?

If not, go ahead and shoot that can into it, and see if it comes on. You can also jump the wiring plug on the low pressure switch and force the compressor to run if it's real low, but don't allow it to run very long this way...if it refuses to accept gas or the pressure doesn't begin to come down within a few seconds of charging, unplug it.

PS, if it does accept charge with the switch jumped, running water from a hose over the condensor will help it pull the charge in faster. As soon as you have 1 can in it, you should probably hook the switch back up...and if you are in the danger range with the compressor running, there is probably a blockage in the system or the compressor is bad...

The low side reading will be very high if the compressor is not operating. And if the system is low, the compressor will not run until it begins to sense pressure in the low pressure switch, then it will engage.

Is the compressor engaging (clutch turning with pulley, or clutch stationary)?

If not, go ahead and shoot that can into it, and see if it comes on. You can also jump the wiring plug on the low pressure switch and force the compressor to run if it's real low, but don't allow it to run very long this way...if it refuses to accept gas or the pressure doesn't begin to come down within a few seconds of charging, unplug it.

Jeff, Thanks for quick reply.
Compressor is engaging. Should I be checking the pressure again on the low side with A/C running? I checked the radiator fins, I think it is dirty, How do I clean it. Also both fans kicked in. Both pipes High pressure and low pressure at the compressor side were hot to the touch. At the fire wall high pressure (smaller diameter) pipe was a bit cooler. What is my next step? Do I still need to recharge?

Another question, Assuming the actuators are bad both driver and passenger, then there should not be any change in the temperature of the blowing air from the vents, right? I played with the thermostats to see if the passenger side remains the same when moved to extreme heat side, blowing air was hot. Now, I think it may not be the actuators.
Thanks again.

I was thinking you just notice the temp difference (warmer on pass side) because it's closer to the heater core...

Yes you need to check the pressure with the A/C on and compressor engaged. At rest the system equalizes and is at very high pressure. The low side is the suction side when engaged, so the pressure drops to around 30 psi if it's working right. When you first open the valve, and the can starts to enter the system, the pressure will shoot up suddenly, usually to around 90 psi or so, or probably high enough to hit the warning zone if the gauge isn't marked in psi.

The small lines are high pressure, they should be hot when the system is running. Where are you connecting to? On my '97, the low side port is down below the air filter box, kinda hard to access. That line and the reciever (the big silver can) should be cold and sweating if things are working right. You shouldn't be able to connect to the high side, so I assume that's the one you are using.

It's kind of a crapshoot to use the charging kits like you have...all you can do is try to add a can and see if it improves. To really tell if the system needs a charge, you have to have an accurate reading of both sides of the system.

Did it gradually stop working right, or was it sudden? Gradual would probably be a leak. Sudden is gonna be a catastrophic leak (which you don't have, if the compressor is engaging) or a blockage, or a control assembly problem in the dash.

I guess you have no condensation runoff under the car with the A/C on? If the system were cooling, but the control system were not directing the air to the evaporator, you'd still see the evap core sweating and dripping under the car...