S-10 Heat Issues

[mcreyaufmiller]

I just bought a 99 S-10 2 door. The heat is a little freaky. the air always blows, but sometimes it is hot, sometimes it is warm, and sometimes it is cold. I know the water is circulating, I know the air is blowing. I think that the door to the heater core is not opening to allow the air to pass. has anyone else had this problem or could help me with this?

[ChevyTech77]

Check the temperature of both heater hoses where they go into the heater core, under the hood, after the truck is up to operating temp. They should both be hot. Even so, these trucks had HUGE issues with plugging heater cores.

A good coolant system flush and back flushing the heater core usually solves it. Sometimes, the core needs to be

replaced because it is just plugged up too much, also.