I have a 1999 2 door Blazer-I only get cold air at all times. Blower works fine. What would be the best way to troble shoot this?What do I check 1st and so on. Need help ASAP Thanks All

 

Sounds like your heater core is plugged up. Take both radiator lines off of the firewall and put a garden hose on couplers coming out of the firewall. Alternate between the two until the water is flowing out of the open coupler freely and has no more sludge coming out. Run the truck for a little while, and add more antifreeze as necessary.

Enjoy your hot air.

 

It is very possible that it is a plugged up core. But before pulling the hoses off and flushing it out, test the temperature on both of the hoses going into the firewall. If they are both hot, then most likely coolant is flowing through them fine. If one is noticably cooler than the other, chances are you have an obstruction.

Also, check the radiator level by removing the cap on the radiator. Do this with the engine cold so as not to scald yourself. Fill the radiator as necessary and bring it up to operating temperature. Fill the coolant tank to just above the HOT line and see how that works.

 

Good call, I forgot that part :lol: