Thanks guys for all the advice I'm just wondering how to go about back-flushing the heater core on my 1998 GMC JIMMY. I'm willing to try this to see if the heater core is plugged. What I don't understand is why I'm getting good blowing heat from the dash vents and then when I turn the knob to winsheild defrost, it blows out cold?
- posted
19 years ago