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Security guy · 10-09-2010, 08:59 PM

I did a search and found some helpful tips, but none seem to answer my question. I have a '99 Silverado with 5.3. I can have the fan on high and the temp dial to cool and it blows alot of air out. If I turn the temp dial to hot, the airflow cuts down to almost a trickle, but I can hear the fan running full blast yet. I'm not getting much heat at all and I actually took the cabin air filter out to see if that was an issue and it does the same thing without a cabin air filter. I may have a blocked heater core which is why I'm not getting much hot air, but why does the airflow almost stop when turning the dial to hot? Any help would be appreciated.

10-09-2010, 08:59 PM	#1
Security guy Registered User Join Date: Mar 2008 Location: Sarasota, Fl. Posts: 441	Another heat problem I did a search and found some helpful tips, but none seem to answer my question. I have a '99 Silverado with 5.3. I can have the fan on high and the temp dial to cool and it blows alot of air out. If I turn the temp dial to hot, the airflow cuts down to almost a trickle, but I can hear the fan running full blast yet. I'm not getting much heat at all and I actually took the cabin air filter out to see if that was an issue and it does the same thing without a cabin air filter. I may have a blocked heater core which is why I'm not getting much hot air, but why does the airflow almost stop when turning the dial to hot? Any help would be appreciated.