strange heat issue....

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Nov 9, 2011 | 07:56 PM

fox128

Thread Starter

Seasoned Member

Joined: Sep 2008

Posts: 324

Likes: 2

From: Iowa

Year: 2000

Model: Cherokee

Engine: 4.0

strange heat issue....

I have searched but not found anyone with the problem i am having in my MJ.....

It blows HOT heat out of the defrost anytime. But when you switch it to vent or floor heat, it only blows luke warm air. Also, when i'm on the gas, it starts blowing out the defrost regardless of what i have the controls set on. getting cold here.....would like to figure this out!

It seems like more than a vacuum leak to me. Any ideas?

Nov 9, 2011 | 08:12 PM

77olds

Senior Member

Joined: Apr 2011

Posts: 813

Likes: 1

From: Lansing, MI

Year: 2000

Model: Cherokee

Engine: 4.0

The blend door is probably not functioning properly. Probably uses a vacuum actuator, and it probably has a leak.

Nov 9, 2011 | 09:12 PM

desertrat71

Junior Member

Joined: Jan 2011

Posts: 35

Likes: 0

From: Las Vegas Nevada

Year: 1990

Model: Cherokee

Engine: 4.0

strange heat issue

sounds like your blend door is not working. could be a bad vacum line at the vacum resavor bottle. my jeep had a crack in the tank got a news one from the junk yard 5 bucks. it is in the front bumper passenger side on my jeep