2002 monte ss. The ac has no cooling or very little. Compressor turns on and and reads about 35lbs so doesn’t seem low. (Have to go back to see if the lines are cold, I kind of think they aren't.) Both heater hoses seem very hot, so must be a flow through the heater core. My question is does this system not have some kind of heater flow shutoff for AC use as I do not see a shutoff valve in the engine compartment. And please no rude comments. Thanks for any help.