Heater Issues

[Rich20001]

Took my 99 Expy to get my coolant leak fixed a while back prior to needing the heater. (Summer) The coolant leak was the hose that goes into the engine so it was an expensive fix.

Now that I need the heat, the only heat I can get is through the defrost vent no matter what mode I select for the air flow. I am getting no flow through the front panel or floor vents.

The rear heater seems to work fine.

Any idea's on what the issue might be?

 

[trdragons44]

hows your vacuum? i know that if your vacuum is low it defaults to defrost so at least you can see out your windshield vs having it directly blown on you.

 

[JUST4FUN]

LOOK UNDER THE BATTERY FOR BAD VACUUME LEAKS sorry caps

 

[dgray69]

isnt there a valve by the heater core that remotely is controled by the dial, that distributes between vents, floor, window ect, is it stuck on defrost, had this problem in my old ford, and an old toyota, never in the expedition

 

[tonydiv]

I have the same issue, but I can't find any vacuum leaks. I was told that the switch can sometimes crap out, so I may head to a junkyard and pick one up to test that theory.