ok guys here I go again. I flushed and back flushed my heater core, had zero heat to begin with, now heat works, kind of. However, when I put the defroster on it blows cold air... I know the heater works, when I let it warm up it gets hot (not as hot as i'd like, but none the less its enough) am I missing something with the defroster?

 

With the defroster on, the a/c compressor runs as well... so, if you heat is marginal, putting it on defrost is probably not going to help. (does your truck have a/c?)

May still have some air trapped in the core. Installing a flush T in the highest point of the outlet line, and using it as a bleeder might help.

 

yes it has a/c, sorry I left that bit of info out. Ill give the flush t a shot. ill let you guys know.

 

Is any air blowing out of the defrost vents? or are you just not getting heat to those defrost vents? Those would be separate issues.

 

there's air flowing, just not hot air