Hi, newbie here looking for opinions and/or help. I have a 2000 Blazer LS and am having some issues with my heat and air. When I was using (trying to use) my heat back during the winter I could not get any warm air. Once the truck warmed up the air would become somewhat lukewarm ( I figured just from passing over the engine) but no where near warm as warm as it should have, definitely couldn't take my jacket off while driving. Now that Summer is here my air condition is doing the same thing but reverse ( very warm air). My blower is working great, my temperature gauge acting normal, and the compressor charged, according to my husband, who is a computer nerd, and not a mechanic, hence my coming to this site for advice. I will say that occassionally for about a minute or so it will start putting out hot or cold but then stops again. I have done some reading on here and other sites, and if I understand correctly there is a control valve/door in the system that opens and closes to let the hot/cold air pass. Could it be that this valve is sticking in the closed position, and if so, how involved is it to fix this and a general cost of what a shop should charge me to fix it. Thanks.

Angela

 

We were just talking about this same sort of issue in a few other threads:


LINK #1
LINK #2

LINK #3

 

Hi, thanks for the quick response. I read all three of the posts in your reply before I posted my question. The thing is that of all the possible causes/solutions mentioned in the three threads they would all effect one or the other (heat or air) but not both, I think. I am going to try all these inexpensive quick fixes just to cover all my bases, but if none of them fix the problem, could it be the control valve within the system, and what does it entail to fix the control valve it it is the source of the problem? Thanks again for any and all help.

 

Hi, there! This is my first time here. Hi, mckysgrl. I bought my '99 Blazer in November of 2005. In mid-December, during a severe cold spell, nothing would blow out of my heater except ice cold air. Fortunately, it was under warranty. The dealer told me they put it on the computer, and it was the "4th solenoid" (can't remember the entire technical term, but close...). It is indeed a part that controls the flap to either close or open, and it was stuck open, letting in the outside air. Apparently this is something Blazers are "notorious for". Since it was a holiday time, they gave me a loaner, and had to order the part, supposedly from out of state, and it took awhile to get. I know for a matter of fact, though, that they have to tear apart the entire dash, because I forgot to get something that I needed in the Blazer, and saw it that way in the shop. Since it was under warranty, I don't know what the cost was, but I would imagine it's quite expensive to do (the labor anyway). Anyway, after they did that, there was still only minimal heat, and they did a flush, and all was well. I'm sorry I can't remember the actual technical term (hubby isn't here right now to ask), but I hope this helps you. If I find out the terminology, I'll post it for you. By the way, I absolutely LOVE my Blazer!

 

A/C and heat are really two different systems. The heat is part of the engine cooling (radiator) system, while A/C includes the compressor and an entirely different (sealed) refrigerant circuit.

For the heat issue ( I know it's summer... but this is important) you should read this information about refilling your cooling system. Even the smallest leak will cause problems over time.

As for the A/C, it's probably low on refrigerant. Topping it off isn't a good idea. It should be checked for leaks and repaired as required. Then vacuumed and recharged.

Hope this helps! If you're doing any of this yourself, speak up and we can steer you through it.

 

Thanks for the info. I am going to check all the simple things this weekend ( not that I expect it will be anything simple, bad luck was invented for me lol) and if none of the simple things are the problem, I am going to put it in the shop on Monday. I will let you know how it turns out. Thanks again for all the help.

Angela

 

Well, I ended up taking it to the shop to be diagnosed and repaired. It turned out to be something called a thermal regulator/ sensor ( something like that), it's on the invoice out in the truck. Anyway, it cost me about $270 to have it fixed. Apparently this part will affect both the heat and the air. I sure was hoping it to be a lot simpler problem. Oh well, you can't win them all. Thanks for all the help and input you guys offered.

Angela