Hi I'm Carol the owner of my 2nd Chevy Blazer I have a 2000 Blazer 4 dr 4x4 and a great truck might I add I bought it new in 2000. I am currently having a heater issue and would love some advice. My heater will not heat until my truck is moving. I crank my truck in the morning and the heater will not warm until I am in drive and moving. Once I am in drive and moving it great and gets extrememly hot quick. I would truly appreciate any suggestions and it has been pretty cold here lately.

 

Welcome Carol!

So your heat output is lacking when you are idling in your driveway... How long do you allow your vehicle to warm up before making this observation? Does the heat work if you drive for a bit and then stop and let the truck idle for a bit?

It is possible that the heater core is partially plugged, reducing the heat output.

I am moving your thread to the 2nd Gen Tech section as the New Member Area is for introductions.

 

I usually crank my truck and let it run for about 15 to 20 min's in the morning before driving when I crank my truck I turn the defrost high and hot. Always before when I would come out my truck would be warm window defrosted and no issue. Now I come out after cranking my truck and freezing air is blowing window is not defrosted so I do the scrap thing jump into my truck and before I can get to the end of my driveway the air starts getting warm and continues until hot. Yesterday I got behind a bus and had to make several stops and noticed that when my brake was on and my truck not moving the air would get coldagain. My truck has to be actually moving before my heat will work.

 

I would have a look at your coolant level in the radiator. This sounds like you may have a low coolant level.

If that checks out, I would look into doing a cooling system flush, really cleaning out the heater core.

 

Thank you

 

No problem! That is what we are all here for!!

Please let us know how you make out. What worked and what did not. It helps others when they are searching through posts trying to find an fix for a similar problem. With out a follow up, no one knows if the advice given fixed the problem.

 

For me, finding that the coolant level was low, was how I found out that my water pump was slowly leaking(never did smell antifreeze). Take a good look at your water pump!

 

Just wanted to let you know I took my truck and had thecooling system flushed and now the heater is working perfectly. I had it checked for leaks and they found none, but my over flow was pretty nasty with some sort of brown thick mud looking stuff. They took it off and cleaned it out. I paid to have my cooling system flushed the beginning of summer but from the looks of my over flow it wasn't done. I have never seen anything like that before.
Thanks alot for your help