Heater blowing cold air

Heater is blowing cold air even with heat on high setting.
Flushed my heater core and radiator already.
No leaks or coolant on passenger side and no smell of coolant in the cab.
Not sure what else can be done aside from doing a heater core replacement.

 

There is a cable that runs under the glove box, it has to clip into place near the blower motor. Last year I bumped that loose and lost heat. Another member had the same issue. If you look under there you will see it. Try that before replacing the heater core.

 

Yeah I just checked it, it’s plugged in and I can hear it turn on when I turn the heat on...

 

When you switch the temp dial, can you hear the motor moving?

I have always made it a habit when adjusting temp or vent position to turn the blower motor off. This keeps the blend doors from having to fight the air while changing position.

 

How do i turn the blower motor off?

 

You can unplug it but I think he means you just turn the vent to zero so it's not blowing air. Are you sure your blower motor is working? You have air coming out of the vents it's just not hot right?

 

Yes I can hear my blower motor working. My vents and ac cents are working, it’s just not hot air blowing out.
I already did a heater core flush and a radiator flush and even emptied and cleaned out my coolant tank.

 

Does the temperature knob feel normal when you turn it? There are little cables back there and I'm just wondering if one broke or came loose. One runs through the firewall and I think you can see it move when you turn the dial. Have you checked that? I'm just going through process of elimination here.

 

Check the cable on the heater control valve (red circle) in the picture that @FirstGenVol posted above. The valve is open when the cable is pulled towards the firewall. With the valve open that hose should be hot on both sides.

If that checks out OK pull the temperature knob from your dash, it just pulls right off. They have been known to crack and it's possible that the temperature knob is just spinning while not actually moving the cable. Amazon has cheap replacement knobs.

 

Yes when i turn from hot to cold I can see it turning the heater control valve on where my inlet hose is at. And I manually turned the heater control valve and it also turned it from hot to cold

 

Is the hose hot on both ends of the heater control valve? If it is, it sounds like a blend door problem.

 

Yes they are both hot
Blend door? Where is that located?

 

This thread and the link to another thread in post #3 will explain it better than I could.
https://www.tundras.com/threads/yet-another-air-blend-door-question.74581/

 

Ok thank you very much everyone!

 

Wha happen? Fixed?

 

Haven’t gotten to it yet! Gonna be home later today.

 

Make sure there is no air in your Cooling system. The best way to do that is to park on a very steep incline so that the heater core is below the neck of the radiator fill cap and started up and run it. any air in the system should come to the neck and burp out.
The heater core is the highest point in the cooling system and air will accumulate there preventing hot water from entering.

 

Ok I’ll have to try this out! So just leave it running for about 5-10min? W

 

Run it till it stops bubbling. 5-10 minutes should be enough.

 

Ok thank you!

 

My first truck back in the day, 97 Dodge Dakota 5.2 Single Cab 4x4 on 33 all terrains, damn I miss that little truck, started blowing cold air at me for about the entire trip home in the mornings during winter until about 1/4 mile from the house when it would finally start to warm up a tiny bit. Turns out the thermostat had failed and was in the stuck open position as designed. This prevented the engine from heating up quickly so the heater would take a while to blow hot air. Replaced the thermostat and the next day, hot air within minutes. Perhaps a thermostat check is in order.

 

I’ll look into that as well thank you!
Just hoping it’s everything but the heater core!

 

How to flush heater core....
https://youtu.be/M9SIafVsqyc

 

ChrisFix has lots of videos with very helpful easy to understand information. He has several videos where he discusses things briefly and fast and then he also has a long detailed version of the same procedure.

 

Yes I’ve done this already as well as a radiator flush.

 

Any updates Karl?