I am not sure if something is wrong with the heater direction control on my wife's 2003 Blazer. I do not drive her truck very often, but the other day when I select the heat direction **** to different positions heat continue to come out the dash vents, even if the floor position is selected. Is this normal?

 

You have a vacume leak someplace, need to check all lines and fittings. Not fun but have to do it.

 

95 96 97 Chevy S10 Blazer Climate Control OEM | eBay
Does yours look like this? Mine does and 10 minutes ago i took it out of the dash i know there is vacuum to mine but doesn't switch between heat and defrost..
I found new ones for 95 bux... But first i need to find out how much vacuum should be at the switch

 

Your hose fell off or broke off of the vacuum tank that is in the drivers side front fender.

There is a hose comming from a t fitting with one leg going to that impossible to see tank in the fender. Plug the hose and replace hose as needed to the tank.

See this thread it has pictures of where the hose connects.
https://blazerforum.com/forum/2nd-ge...hose-go-64903/

 

I checked the vac lines under the hood and they are all connected. My 4 wheel drive does engage correctly. Maybe the vac line is disconnected by the switch? Just to be more clear, the heat/air does divert to the different locations but there is always heat/air coming out of the vents.

 

shawgf,

You don't have a vacuum problem. I had been having the same problem with my 98 and just ignored it because I thought it was vacuum related and didn't want to screw with it. Heater core went out and I had to change it to preserve peace in the house. When I removed the HVAC module from the car I found the diverter door that directs air from the vents to the floor was broken and laying in the bottom of the air box. $25 at the dealer and works good as new. Have to remove the air box completely to get to it. I had to remove the entire dash but a better mechanic (may) be able to get to everything without removing all of it. Good luck. It's a PITA.

 

Well the truck is my wife's and I do not drive it very often. She seems to be fine with it being that way. So until something else happens, I guess it will stay that is way. Thanks guys

 

Good news for you. I've got a 98 jimmy that has ben doing the same thing for a year now andjust last week I opened the glove box to change out the wiper relay and found the problem. Behind the glove box is a conector with all the vacume line coming from the directional switch. It had simply gotten caught on the radio wires when someone changed it out and pulled loose. The other end of the conector was like a good 6-7 inches away. I plugged it back in, after rerouting it back from around the radio wires and it works now. I couldn't believe it, I went to change a wiper relay and ended up with defrost and floor vents again. It sucks only having dash vents, especially in the winter or when its raining so fix it and your wife will be so happy with you....

 

Thanks for the update. I will look at this for sure...Glenn