No Heat

[sntrym]

One other thing to check - Follow the hose from the back of the intake manifold to the heater core. Does it go straight in, or is there a hose assembly that it goes to? If it goes to an assembly, this is the heater core bypass. Using vacuum, it's supposed to open to let coolant flow to the heater core when the A/C is not on. When the A/C is on, it closes and routes the coolant to the radiator to provide colder air. Not all trucks have it, but some do. If the bypass is bad, everything will work fine, but you won't get heat. This happened in my Yukon. I remove the bypass and let coolant flow through the heater core all the time, and I don't have any A/C problems.

 

[Brother Al]

^^^great point, but that wouldnt cause his lower radiator hose lacking heat issue.

 

[sntrym]

The lower hose is pulling from the radiator, so I would expect it to be much cooler than the other hoses on top since they are all coming from the engine with engine heat. Without a temp measurement, it's hard to say if "cooler" is good or not.

 

[Brother Al]

Somewhat true, but I can tell you that the lower hose will still be hot enough to scald you at operating temp... it will still be well above 170° with the best aluminum, multicore rad

 

[sntrym]

He said all the hoses were getting hot now after the radiator swap, so he must have had something plugged up in there. Still hasn't solved the heat issue though

 

[Brother Al]

Ah, missed that later post.

 

[erich7667]

Update, I replaced the control panel and still no heat. I'm glad I did cause the one that was in there was held up by zip ties and was falling apart. All hoses heat up fine, maybe try doing another flush.

 

[92silverado1500]

Thank you. I changed the blend door actuator. Yes I can see it rotate. This will help thanks again

How did you change the blend door actuator? Did you have to take out the glove box to get to it?