Car with 137K running great. Had the heater on and was taking a long winding
off ramp from the freeway and all of a sudden the AC button light comes on along with the AC. Since then the hot air comes on only for a few seconds (when requested) then goes cool, even with the temp setting to 85. Any ideas?
Thanks

 

check your heater valve up against the firewall. it may not be moving. there's an actuator under the dash connected by a cable to the valve. sometimes that actuator goes bad and leaves teh valve closed or partially open which results in not so hot air.