Hey so I'm new to stangnet and I've been having problem with my 1999 ford mustang gt. 1st my coolant/radiator light is on and don't know what's the cause of that 2nd when I turn on my car it idels around 1k but once I time on the Ac it drops to like 500 rpms or sometimes lower to where it might stall another problem I have is my a.c. works but it only comes out the defrost ventsit does blow from the normal vents no matter what setting I have it on please help I've been trying to find this problem for a week now thanks!!