I have a 2000 silverado and I am having some trouble with the heat. As long as i keep the blower on 2 or 3 it will blow out heat, if I turn it up any higher the air starts to cool off. The temp is running normal but the radiator hoses are always soft. Is the thermostat stuck open? I need to fix this before wintercomes so any help would be great. Thanks

 

Could be thermostat, but I would be looking closer at the heater core itself. Its probably partially plugged up and needs to be ither flushed, or replaced. It sounds like its not letting enough coolant to flow through at a time and when the blower is in high, it cools the antifreeze completely before it leaves the heater core

 

Ill try that. As far as the system not building pressure could that be caused buy a plugged heater core? The hoses are always hot but never hard. It did this last summer to one day we put the a/c on and later on that night when we wanted heat there was none but it started working after a few minutes. Thanks again.

 

No pressure is probably the result of a bad rad cap. It is what holds the pressure, and relieves the excess pressure to the overflow bottle

 

I thought that was my problem to so i replaced the cap and still no pressure. I guess ill just keep tryin and thanks for all the advise.