My 3002 Honda Civic Ex overheats onlyI’ve had the head gasket replaced
My 2002 Honda Civic Ex engine overheats during freeway driving of 30 minutes or more, only when the a/c is on high. The air starts to blow hot, I turn the heater on and the cooler gauge returns to normal, instantly. I’ve had the head gasket, radiator, radiator cap, and thermostat changed. I’ve taken it to several shops, no answer. Please HELP!!!