My heater does not work started out the heat wasn't functioning?

Hi,

What you described sounds like the coolant level is low. Have you checked it? If it is full, the first thing I would suggest is flush the system and replace the thermostat.

Let me know. As far as a flush, here is a link explaining how it is done:

https://www.2carpros.com/articles/coolant-flush-and-refill-all-cars

THis guide will help us fix the heater operation

https://www.2carpros.com/articles/car-heater-not-working

Please run down these guides and report back.

Driver side blows cold air while passenger side blows hot air when heat is on. I changed the blend door actuator for driver side still blows cold air. I even moved flap for blend door by hand to see if changing the position would make hot air come from driver side vents. But it did not. Still blows cold air I am at a loss for what it could be.

Okay, so I flushed core like you said from both sides small amount of debris cam out but not a lot to plug it. still the heat only works on passenger side. I turned A/C on and only cold air came from passenger side. Is there some sensor in there that could be bad why it only blows fan air on driver side?

Nope, no sensor. You said you moved the door manually and no heat. That leaves only the heater core.

Roy

Heater/Vent Module Replacement

Removal Procedure

1. Drain the engine coolant. Refer to Cooling System Draining and Filling See: Cooling System > Removal and Replacement.
2. If equipped remove the auxiliary battery.
3. Reposition the inlet heater hose clamp from the heater core.
4. Remove the inlet heater hose from the heater core.
5. Reposition the outlet heater hose clamp from the heater core.
6. Remove the outlet heater hose from the heater core.
7. Remove the I/P carrier. Refer to Instrument Panel Carrier Replacement See: Dashboard / Instrument Panel > Removal and Replacement.

I changed temperature blend door all set thank you. Now I don't have to freeze!

I have changed the thermostat and flushed the system the truck is coming up to temperature okay, still getting very little heat.

This sounds like you have low engine coolant or the temperature blend door actuator stopped working but to but sure this video and guide can help us fix it.

https://youtu.be/SNRb6pSwYuU

and if the temperature blend door needs replacement here is a guide that can help with diagrams below to show you on your car.

https://www.2carpros.com/articles/replace-blend-door-motor

This guide can help as well

https://www.2carpros.com/articles/car-heater-not-working

Check out the diagrams (Below). Let us know what happens and please upload pictures or videos of the problem.

Yes, the truck was low on coolant got the heater working again thank you

I have the manual temperature control with two sliders. Yesterday I noticed the system was blowing cold air even though I had the sliders all the way up to hot. When I touched the slider and adjusted them down a fraction of an inch, the system immediately started blowing hot air again. This problem continued for about a day where the system would work for a while, then stop blowing heat until I adjusted the selector down a bit, then back up. This morning the selector no longer makes any difference and my system blows only cold air.

The slider is for changing the position of the blend doors between heat and cool and it has since stopped working. You would need to check why it has stopped, which could be due to some linkages going bad or out of adjustment.

These guides will help us fix it

https://www.2carpros.com/articles/car-heater-not-working

and

https://www.2carpros.com/articles/replace-blend-door-motor

Please run down these guides and report back.

After warming up heat blows hot air, approximately fifteen minutes later it blows cool air, then approximately fifteen minutes later it'll blow hot air again. It continues to do this. What could be the problem?
Thanks

Hello,

This could be problem with your blend door actuator. I have included a couple of links down below.

https://www.2carpros.com/articles/car-heater-not-working
https://www.2carpros.com/articles/replace-blend-door-motor

Please go through these guides and get back to us with what you find out.

Thanks,
Alex
2CarPros

Will do. thanks so much.

Just wanted to say thanks for your quick response/advice. It was the thermostat and I found out the hard way that my thermostat/housing is all one piece. But it is fixed.

have replaced thermostat checked fuses still no heat?

Only one hose going from the engine to heater core gets burning hot to touch, the other only gets warm. it never runs hot always goes on the gauge where it supposed to. i put anti freeze in it still no luck. i am at a loss. what do you recommend for me to do?

Good evening,

It sounds like the heater core is clogged. I would remove both hoses from the heater core on the firewall. Then use a garden hose and run it through the core. Run it both ways several times until the water is clear and has an even flow from running it both ways.

https://www.2carpros.com/articles/car-heater-not-working

Roy

I am wanting to know where the actuator that adjust where the heater air output is located.

Drivers side of HVAC case under dash. Check out the diagrams (Below). Please let us know what you find.

I bought the truck this past spring and with the days getting colder noticed that my heat does not work as it should. Coolant level is fine, the hoses get hot. The truck has very little heat when idling but gives off more as you are driving around. Even full blast while driving around, it never gets warm enough to the point where i would want to take my coat off. I doubt it would even melt away ice. I saw someone else on this site have a similar problem and they said they "flushed" out their heater core and it seemed to work fine after that. Is that a feasible solution or is there something else going on here?

We need to first see how hot your truck is actually getting. What does the gauge say? It should run about 210 degrees. If it is, feel of both hoses going into the heater core, through the firewall. Is one hot and the other cool? Or cooler? If so, the water may not be circulating through the core. Keep in mind that if the water is circulating, and the blower is on, blowing air through the core, the water temperature on the outlet side of the heater core will be slightly cooler. If the water is not circulating through it, one will be considerably cooler. If this is the case, I only recommend replacing it. If it appears to be circulating, I would start checking the operation of the blend door in the evaporator case. If it is mostly closed off to the core, little or no air will pass through the heater core, thus no hot air will reach your cold face or feet try that. If the truck is, in fact, not reaching 210 degrees, replace the thermostat.

Also, it could be a blend door actuator acting up.

https://www.2carpros.com/articles/replace-blend-door-motor

and

https://www.2carpros.com/articles/car-heater-not-working

Please run some tests and get back to us so we can keep helping you.

Cheers,

Truck is reaching the correct running temperature of about 210 degrees and does not over heat. a bad thermostat is unlikely. The water does seem to be circulating because both hoses are getting hot. The outlet hose is slightly cooler. Where would i find the blend door, and how would i go about replacing/fixing it? What would stick out as obviously wrong with it? Thank you.

in my experience if the heater core is plugged, you will get heat for a short time and then the air will blow cold. this is because there is flow in and out but very little out. so the core fills up with coolant and when you turn on the heat it initially blows hot but the coolant is stagnant because of the output. so if you turn the blower off for a bit and back on you will get heat for another few minutes. is this happening to you? also, if the thermostat is stuck opened then coolant will not reach operating temperature or will take a very long time to reach. it depends on the cooling system. if you have good flow and a heavy duty radiator (three rows inside) then the coolant will never get hot. also, i have flushed several cores over the years mostly using the water hose. if it is easy enough to remove both heater hoses, why do you not block the hoses and check the core for flow using either air or the garden hose. you will know immediately and you will not lose much coolant. if you use water be sure you do not put full steady pressure. short bursts. if it is clogged and dirty be sure you flush the complete system with the Prestone flush kit. flush it, do not just drain it. let us know how you did.

The blend door is in the EVAP case. Do not try this if you are scared. The dash is going to have to come out. That is a process all by itself. The AC system will have to be discharged as well. Remove the case from the firewall. Before we jump into that, lets check the operation of the actuator first. The door in question is controlled by an electric actuator that receives its signal from the AC control head. I do not have the information in front of me because it is Sunday and I am at home, but I think it is on top of the evaporator case and nearly impossible to get to. I will know for sure tomorrow when I get to work and can look at my computer there. This is way more likely than the actual door being stuck, although that can happen. Rats can build nests in there and block the door. The blower can suck a Sonic napkin out of the floor into the case and there is no telling where it will end up. But, before you go to that trouble, check the actuator. Try turning the temp control from hot to cold. (with the vehicle on) Do you hear any change at all? listen closely behind the glove box for anything. Start there.

The other day i flushed out the heater core with a garden hose. Used short bursts of water pressure. The heat seems to be working much better since i have done this. Cross my fingers, hope it stays that way.

just a footnote: if the heater core was in fact plugged, then the coolant system may very well be in dire need of flushing. otherwise the problem may reoccur. good luck.

Sounds like my issue. Found out the problem was the "air door actuator", GM P/N 52474810. This part is about $100.00 at the dealer. Save some money and get it at O'Reilley's Auto Parts for $46.00 with a lifetime warranty! Also, you can check eBay and find them there. The actuator is underneath, near the center of the underside of your dash accessed from the passenger side. You will need to remove the three screws that hold that cover on and you will see it there.

Here is the post that turns the flap inside. You can manually move it if you are in a pinch where it is real cold and you need heat until the new part goes in.

Another picture here shows part of the problem. I believe the problem is that little blue gear which is attached to some type of potentiometer that has contacts exposed which gets grease in there. Also note another indication it was going to fail: Check the motor where it has markings on it. It says: "China" bet the whole unit was made there.

Here is the new one installed. This one I bought from O'Reilley, using the GM part number 52474810. This part also has a lifetime warranty! :)

Here is the new one: https://www.amazon.com/gp/product/B0012PQX3U/ref=as_li_qf_sp_asin_il_tl?ie=UTF8&tag=2carprcom-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=B0012PQX3U&linkId=484be50463f80c7d6cf715954050752d Please let us know what happens.

Just wanted to tell you that the pictures are great! They helped me fix my actuator problem in short order. Thanks again.

No problem bdome! Post anything else that you may have questions or problems with!

Heater not blowing hot air.

Is it a dual climate control?if so are both sides not getting hot?

These guides will help us fix it

https://www.2carpros.com/articles/car-heater-not-working

and

https://www.2carpros.com/articles/replace-blend-door-motor

Please run down these guides and report back.

Is it the left side not getting hot?Usually the left blend door actuators go out on those trucks.

This is correct that the blend door is most likely the issue. Below is the info from the manual on how to replace this. Please run through this material and let us know if you have other questions.

Here is a guide that will help with this as well:

https://www.2carpros.com/articles/replace-blend-door-motor

Below is the info from the manual. Thanks