Heat is always on!

Ever since I bought the Blazer I noticed my feet always getting hot. Now I noticed that its because the heat is always on. The blower is always blowing or something.. I put the temp control to the coldest setting and I turn the main control to the OFF positon.. And I still get hot air. Any suggestions?
Thanks
- Tom

I think it may be your blending door. I've never had the problem, but I would do a search for that.

put a ball valve on the heater core, if you wanna feel good about it, put one that is either stright flow or 90, put one one both sides and connect with hose,

put a ball valve on the heater core, if you wanna feel good about it, put one that is either stright flow or 90, put one one both sides and connect with hose,

What? The blending door is electric.

yes it is, but cut off supply of coolent to heater core and no more heat! not sure of his year, but mine (98 pu) is vacume acuated, and i dont plan on fixing it untill the moter swap, to much work for a 20 min. "cheating" fix, i do open it up once a week in the summer and let coolent circulate through it

yes it is, but cut off supply of coolent to heater core and no more heat! not sure of his year, but mine (98 pu) is vacume acuated, and i dont plan on fixing it untill the moter swap, to much work for a 20 min. "cheating" fix, i do open it up once a week in the summer and let coolent circulate through it

No, you fix the actual problem, not divert coolant flow to fix it.

Your blending door is NOT vacuum operated, it is electric.

sorry should have stated that better, i know the blend door is electricly controlled, but there is a vaccume switch back there gone bad (not sure what its for, one problem i accually didnt look into myselfe) and that the heat is on due to this, so i just shut the flow off, plunty of people have done it, and ive seen a few write ups on it, i know its not the correct fix, but it works, and i dont feel like getting back to that point...yet, i will fix it correctly this summer, but i wasnt taring it apart between late augest after school started and winter, i wouldnt of finished

BlazerLT, I have the exact same issue on my 2000 Jimmy SLE. I have heard of this blending door too many times, but don't know exactly where it is or how to get to it. I have been told that the foam strips could have fallen off completely the door, or at least slipped causing the door to stay partially open. I know it is fighting the air conditioner. Do you think you could enlighten an old dumb guy? Exactly where the heck is this thing.

Thanks everyone... I'll have to check the blending door issue... and get back to this post after I see if thats the problem.
thanks
-Tom

BlazerLT, I have the exact same issue on my 2000 Jimmy SLE. I have heard of this blending door too many times, but don't know exactly where it is or how to get to it. I have been told that the foam strips could have fallen off completely the door, or at least slipped causing the door to stay partially open. I know it is fighting the air conditioner. Do you think you could enlighten an old dumb guy? Exactly where the heck is this thing.

I will be completely honest with you, I have never worked on the blending door personally.

Just don't want you to think I didn't get your post.

Maybe others have more intimate knowledge on its' location.

Help Rick out guys.

The actuator motor is locatedon top of heater case. Remove instrument panel. Unplug electrial connector. Removeactuator motor. To install, reverse removal procedure. I think the vacumm line you see is for the fresh air door. This open close to take outside air in, in recycle mode this door opens to take air from inside.

I have a 99 blazer and I noticed that I don't have a recylce mode on my Instrument Panal for AIR/HEAT.. I looked at my buddies 99 Jimmy and he was having the same problem, but he has a recycle button, when pushed the problem goes away, causing no airflow/no extra heat. Therefore is there a way I can switch out panals from a wrecked 99 Jimmy or another Blazer if others have the recylce function?

I got the same problem. Both my 2000 s-10 and 2004 blazer does the same thing. When everything is off it blows a slow stream of hot air. I just keep the top vents turned on so it wont blow on my feet. Anybody know of a fix?

On my 96 blazer I had to replace the blend door motor. It really is not too bad. As previously stated you need to remove the dash completely. Again that is not too bad. Then remove the heater core. Behind the heater core and just below the metal part of the fire wall (below the window) and just on top and slightly behind right side of the air housing (behind the heater core) the is the blend door motor. About 55.00 from GM. There are 3 screws that can be a real pain to get out. I used phillips bit (the type that slides in a 1/4" bit). Believe this a very dueable job. It can be done in about 4 hours total. *****caution*****. I do not know how to take the instrument panel frame off without breaking the flasher button. If you do break it, you need to replace the entire turn signal switch which cost me $100 at the junk yard. Good luck and email me if you have question when doing it. You guys were such good help to me, I hope I can return the favor.

My Blazer does this same thing. Kind of annoying all summer and I could fix it but with fall/winter coming up, I might as well wait till next spring!

I am not sure about your control exactly but some say max air , normal air. Max air is recylce and normal is outside air. Some truck let the fresh door be open in most mode for air vent. Not sure of your complaint but max air recylce inside air and normal take in outside air which will most likey be warmer air. The blend air door is only moved with temp control.

So if i run Max Air it will recycle the air in my truck? and not run the AC also?

In regards of my last post.. The max air does not stop the air since it causes more air to come through due to the fact that it turns on my fans and the off setting is on the same dial as max air. so i refer back to my orginal question of can I switch out my temp console with another blazer or jimmy of the same year with using all functions?

Yea don't know that one. Yes max air is ac in recylce mode. The door is set to be in outside air as default position for fresh air vent. In your truck the fresh air / recylce door is vacuum operated. Never seen that switch to a push botton switch.

Well, did you fix the prob?

I know this sounds redundant, but I'm another one that had the same problem! However, mine ended up an easy fix - blown HVAC fuse. On my '98 it's #21 - a 10Amp in the fusepanel on the left side of the dashboard. The actuator for the ventilation positions worked OK (defrost, heat, dash ventilation, bi-level).

Thinking about it, if it seems that adjusting your heat makes no difference in the air temperature, or turning on your A/C doesn't change the temp either, then check the fuse. If it's not the fuse I mentioned it may be somewhere else in the circuit.


IVIr_Evil']Thanks everyone... I'll have to check the blending door issue... and get back to this post after I see if thats the problem.
thanks
-Tom

Well, did you fix the prob?

I know this sounds redundant, but I'm another one that had the same problem! However, mine ended up an easy fix - blown HVAC fuse. On my '98 it's #21 - a 10Amp in the fusepanel on the left side of the dashboard. The actuator for the ventilation positions worked OK (defrost, heat, dash ventilation, bi-level).

Thinking about it, if it seems that adjusting your heat makes no difference in the air temperature, or turning on your A/C doesn't change the temp either, then check the fuse. If it's not the fuse I mentioned it may be somewhere else in the circuit.


AWESOME!! I will check it out ASAP and let you know what I find. I hope its as easy as that..
thanks alot...
-tom

just checked the HVAC fuse. i Had 2 of them.. and both of them were good.. kinda hoping that was the prob.. but no such luck.. thanks anyways though.
- tom

I don't know if anyone will check this thread but I thought I would add my two cents. I have the same problem on a 98 blazer. The blend door actuator is on top of the heater case behind the glovebox. You don't have to take the dash out to get at it. There is a little metal tab close to the latch. Push it and the glovebox door will swing down. There is a vacuum actuater that is immediately visible. The actuator is behind it. It only has two screws that you can see so don't waste time feeling in the back for a third screw. At least Chevy did something right. I have replaced the climate control computer and this was not the problem. My blend door actuator is on its last legs but it is not the problem either. For some reason it is getting the signal to hold the door open towards the heater core and I have not found why. Don't buy a Haynes manual as they are worthless. I have been considering buying a Chilton because I have one for my truck and it has more detail and useful information. Has anyone made any progress?

For some reason it is getting the signal to hold the door open towards the heater core and I have not found why.

How do you know this? So I can test mine.

thanks
- tom