If your system worked recently and now it doesn't, you're probably low on freon. This could come from a leak in the system. Add a can of freon with dye in it to identify a leak and then replace the leaking part, then vacuum the system, replace the receiver/drier, add freon and see if that works. Yes, one or the other or both. See if you can find a gauge to check the low pressure side. There should be a port near the receiver/dryer. If the pressure is low, add a can of 134A to see if the thing start running, even briefly. If the compressor starts cycling on and off while you're adding 134A and/or after you're through, it's probably still low. If it's already fully charged and the compressor clutch won't engage, there's probably more to it.
1997 s10 4.3 Chevy blazer. what inlet does the freon go in. the one on the aluminum tank where the hose from the compressor goes into it?
I've got a better question, why is this question in the Chevy venture forum ?
Control problem, blend door not working are the places to start
it needs to be recharged
change alternater first, then ecm blowed
check the temp guage if low change the thermostat
You need to have your refridgerant recharged
Check Antifreeze level..make sure there are no leaks under the vehicle.
The heater valve could be failing to open for one reason or another.
Low coolant in the system. Defective heater control valve. Clogged heater core.
Either a faulty thermostat or you have a low coolant level.
If it does blow just not cold air you should see if it needs to be recharged