Hi,I have a2000 blazer and I'm not getting any heat. I had this problem last year,but lived throught it. The gauge goes to the normal point,but just blows cold air or bearly warm air. I did notice last year if I turn the fan off for a minute then back on I would have heat for a few second. Does anyone have any ideas? I don't want to freeze my *** off this year too.

 

sounds like your heater core is partly block. Unhook the 2 heater core hoses on your firewall or at your block. hook up a garden hose and flush out the core. Hook it all back up, run the truck and after it cools add more antifreeze

 

^^^dead on.
flush and fix..all set.

 

I'll give that a try tonight and let ya know. There has been frost on the truck the last two mornings.

 

When flushing the heater core...keep the water pressure and volume at a low level. If you put alot of water pressue you could easily blow-out the heater core and have a really fun job ahead of you....not to mention a big mess to clean-up in the interior.

"Easy as she goes" is the thought here.

 

I did just this last night. We removed the hoses from the motor, not the firewall just to make sure the hoses were not clogged. We first used the line that flows to the heater core, it was 100% clogged, no air was coming out the other end. Then we went to the other hose for a reverse, then all of a sudden everything just shot across the garage. Then we flushed the core with water a few times and then again with air, hooked it all back up and instantly had heat. No more cold mornings or adding miles to my 2012 LTZ.

 

Well I flashed out the core last night and it was clear. The stuff in the system is rusty. Theres not alot of flow in the rad,so I guess I will be playing with it this weekend. I don't really want to pay the guy at the garage a 100 bucks to flash it out.

 

if the core was clear and running well its not the problem. could be the fresh air vent or actuator. Mine was doing this last week and was getting frustrated also. Put the **** on hot, punched and walla, heat. Empty your glovebox. open the box all the wayopen(push the spring on the top of the box opening) in there will be vent doors with vacuum lines hooked up to them. Turn the vent control **** and seeif anything is moving, with truck running. this may help you figure things out about what goes on in there

 

As above: rotat temp control from hot to cold and if the blend door does not move....think you found your problem.
Getting the little motor out is a bit difficult due to the very limited space. And I have read that an exact replacement is not available. You may be able to fix yours. I found a bad solder joint on the little motor was the problem, 10 seconds with a soldering iron and it was working again. Perhaps you may be as lucky.

Several threads on how to get the actuator out...just need to search for them. Do you have someone with small hands to help?

Good luck.