No Floor heat 98 Blazer 4.3L 4X4


DRGREENTHUMB1001
11-08-2011, 12:56 PM
I have no heat coming from my floor vents.

I have heard some people here say it may be a vacuum issue dye to a broken line and others have said the door/flap inside the dash that controls air flow to the floor is broken and wont open.

How would I know for sure? Air flows from teh dash vents and the defrost and I can switch between them, but When I set it to the floor dial it just blows air thru the defrost.

I have checked the vacuum lines that I can see from above the engine and they are ok but I have not gotten underneath to see if I've missed anything.

If its a broken door in the dash I've read that some have had to take teh dash aprt and break the assembly where the door is in order reinstall a new door and fix the assembly via Glue? TAPE?
Could you just take the broken door out and leave it out? Or would it always be on floor, which isnt that bad really, except when you would need defrost to work...

Rick Norwood
11-08-2011, 06:10 PM
If you have a vacuum leak, you will most always just have defrost. The fact that you have air blowing through the vents tells me you have a door that is not opening. It is either stuck or not opening due to a vacuum leak or possibly an electrical issue.

DRGREENTHUMB1001
11-09-2011, 10:09 AM
So Door not opening, but it sounds like to you the vacuum is ok, which is my theory as well.

So I guess I will just have to tear apart dash? From what I have read, the heater door on post 98's is made out of plastic, is cheap and breaks where the linkage hooks into the door. Would you surmise that it may be that, or if not its a problem with the door in some way?

Rick Norwood
11-09-2011, 05:01 PM
I don't own a '98 so I can only answer generically. I would use a little caution tearing into the Dash. If you don't have a good small socket set with lots of extensions and swivels, it could be a real PITA.

The A/C Control panel is very complex. It could be anything from a vacuum leak under the dash to something broken or simply stuck.

If you do go for it, go slow and be very careful, and allow lots of time. Those pesky plastic pieces are brittle and break easily, and the screws strip out very easily too.

rabbit507
03-09-2014, 12:53 PM
I have no heat coming from my floor vents.

I have heard some people here say it may be a vacuum issue dye to a broken line and others have said the door/flap inside the dash that controls air flow to the floor is broken and wont open.

How would I know for sure? Air flows from teh dash vents and the defrost and I can switch between them, but When I set it to the floor dial it just blows air thru the defrost.

I have checked the vacuum lines that I can see from above the engine and they are ok but I have not gotten underneath to see if I've missed anything.

If its a broken door in the dash I've read that some have had to take teh dash aprt and break the assembly where the door is in order reinstall a new door and fix the assembly via Glue? TAPE?
Could you just take the broken door out and leave it out? Or would it always be on floor, which isnt that bad really, except when you would need defrost to work...

I'm wondering if you found out what was causing this I have the same problem any help will be appreciated :runaround:

Thomas Sams
04-04-2014, 12:27 AM
I think if air is not emitted then air fan is out of order that's why this thing happened you must check the by the mechanic i hope air flow problem is solved..

Add your comment to this topic!