1998 Chevrolet Suburban "heat defrost front back 98" Questions

heat worked fine but my dash vents defaulted to the defrost vents for the windshield. What I found was that this and my 4X4 is actuated by vacuum. Look under your hood on the passenger side up against

...heat & ac Look ,behind the glove box,on top of the hac box,toward the center of the truck,it is a flat box,with a multiple wire plug in it,it is the temp door actuator motor,that turns as you ...

defrost vents. Until the cold air would only come out of the defog vents all the time. Then eventually the air started coming out hot all the time last winter. During the winter I didn't mind but It's

...heat, and I want to replace the heating core, need directions Heater Core REMOVAL & INSTALLATION CAUTION Never open, service or drain the radiator or cooling system when hot; serious burns can ...