Help!!
 

Hello All,
I have purchased a 1998 Blazer, RWD, 4 door, with the 4.3 liter V6. I have found a multitude of issues, and I am hoping, someone can point me in the right direction, with the first. I have no heat, and I can only seem to blow air out the vents. When I change the knob to the defrost setting, nothing blows up to the windshield. I know the thermostat was changed before I bought the car, I am not overheating, both my heater core lines are hot, WHERE Do I Begin??

Sounds like something is wrong with your blend door.

could be the blend door or it could be a vacuum issue. check all your vacuum lines and make sure there not degrading and falling apart. you can find 2 near the brake booster hose.

And with your words of wisdom, I found a rotted vacuum line running from the top of the intake, all the way over to the fender, $7.00 for the hose, and I have heat, and defrost again, no more driving blind in the rain. Thanks for the guidance.