why heater/defrost cools back down after vehicle stops at red light or otherwise stops for a time.

2007 DODGE STRATUS
134,000 MILES
Avatar
FLEACOLLAR
  • MEMBER
  • 1 POST
heater/defrost warms up as engine does normally, but cools back down when vehicle slows or comes to a stop.
Nov 17, 2011 at 3:06 PM
Advertisement
Avatar
DRCRANKNWRENCH
  • ASE Certified Mechanic
  • 3,380 POSTS
  • ASE Certified Mechanic
The heater works off of engine coolant which gets cooler when at idle.
The temperature is kept at operating temperture by the thermostat so it does not cool down too much at idle. More than likely you need to replace the thermostat which is probably stuck open.
Nov 17, 2011 at 3:48 PM
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.
Ask a Free Question
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.