AIR con trouble
 

ok where to start .Having trouble with my air con on my 69 catalina,the forward facing vents work great on all speeds but i cant seem to get any air or heat through the defrost vents at the base of the windscreen any ideas why?

On AC cars airflow distribution is controlled by engine vacuum so make sure the line to the back of the carb is connected and that the check valve is working and not mounted backwards.

There is an air distribution diaphragm under the passenger kick panel. That is what controls which vents are opened. If it leaks, that is likely the problem.

Ok which way should the vacuum check valve face arrow pointing towards the engine or away from the engine ?