1999 Mercury Marquis Heater blower problems

1999 MERCURY MARQUIS
120,000 MILES • V8 • FWD • AUTOMATIC
Avatar
SARA BROOKS
  • MEMBER
  • 1 POST
Heater blows hot air when on cold airconditioning settings or when just vent is on during warm weather or whatever. Why isn't heater turning off and cold air or vent comming on when I use these settings? It is strange that during warm temperatures in the summer that the heater is comming on when I try to cool the car down or just use vent outside air. Help please!

Thank you!
Mar 13, 2010 at 5:15 PM
Advertisement
Avatar
JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Check the blend door. It determines if you get AC or heat and is located near the heater core.
Mar 24, 2010 at 8:16 AM