79 300d climate control
 

I have a problem with the climate control on a 79 300D. It doesn't automatically come on. If I push the auto low button it comes on and stays on. The same if I push the auto high or defrost buttons. I can turn the thermostat dial up and down and nothing happens. So basically I have to control the heat by turning the auto low or high on and then shutting it off when it gets too hot. The air conditioning compressor doesn't have the belt hooked up and I believe it is shot. I know this would effect the auto climate control in hot weather, but that hasn't been an issue here. Any input appreciated. Thanks, Trent.