Taggart

Can anyone advise the fuse and/or relay associated with the hot air blend door? It came to my attention on the first cool, rainy day of fall recently that the system won't blow warm air, regardless of the temp and vent settings. I've got the auto system with dual controls. Any advice on things to check before taking it in to the shop would be appreciated.

gDMJoe

Sounds as if the blend door may be stuck.
.

Blckwlf

Are you getting air flow?
Have you checked your heater hoses? If one is hot and the other isn't it's your heater core.
Are you sure you aren't overcooling? Check your thermostat.
The blend door actuator is usually under the radio by the floor vents on the passenger side of the dash. Pull off the plastic, and watch it rotate it's pin.
You can cut into the heater box behind the glove box and actually look at the blend door, that's really the only way to be sure the blend door is broken or not.
I just went through this with my truck and turned out flushing the heater core with a radiator flush kit did the trick.

Taggart

Both hoses are hot, coolant temperature is normal, and air flow is normal, which is why I'm thinking it's probably an electrical or mechanical problem with the blend mechanism. It was just working a month or two ago.

tanked_darren

I did read the comments, but just the title alone points to BLEND DOOR problem.

Blckwlf

The title alone doesn't point to the blend door, the blend door makes the list but it could be several issues.
His last post though, would lead me to believe it's the blend door or blend door actuator.

Pull off the plastic below the dash by the floor vents and watch the actuator as you turn the ****.
Then to check the blend door you'll have to cut a hole in the hot box behind the glove box and look at it.

I literally just went through this with my truck, checked everything, thermostat, hoses, coolant leaks, blend door actuator, even cut a hole to look at the perfectly intact blend door. Turned out the heater core was plugged or had air in it. A good flush with a radiator flush kit and my garden hose worked.

If you don't wanna cut a hole in the dash under the glove box, you'll be pulling the dash off.

markksheets

I have all the symptoms of a blend door issue. Great A/C no heat. The heat in the roof (Expedition) works but no heat to floor or dash. I opened up the dash and cut a small hole like the mickey mouse youtube videos, the blend door works fine, but no heat. It is running at normal temp.


Any Ideas?


THX,
Mark

steelerz1

Check coolant level