Sounds like the blend door!

 

im having problems with my heat right now after the a/c compressor locked up on me. the heat worked great before hand. it would never change positions from defrost to floor or anything but it worked pretty good just stayin on 1. i cant figure out what it could be either..

 

Every single blazer i have ever rode in (probably 5) have always sat at the temp yours is at in the picture. My 97 runs right there and so does my 01 blazer. I have changed the t stat and temp sensor 3 times and it changed nothing. There is two temp sensors tho, one right next to the t stat (which i thought was for the gauge) then one on the driver side of the block by the 5th piston. Thats the only thing i have not changed that has to do with the temp other than the gauge.

So this problem is obviously hereditary with blazers. my heat is good tho however and i know my engine is getting to 195 because i used my temp reader to check the temp of the hose going to the t stat. Which is something you should do as well if you didnt already use the scan tool for that.

just thought i would throw that in there in case you were worried about where the gauge is at.

 

The temp gauge reading is low, but that has nothing to do with why no heat....I mean it is just a gauge.
The heater core hoses are hot, so t-stat must be somewhat working. But the radiator being hot on one side and cold on the other does not make much sense. One side should be a bit cooler, but not hot & cold; same with upper and lower radiator hoses...I think there should be some difference, just not a huge amount.

So like others it seems to be the blend door. I do not know the setup in a '96, if it is different from my '02. You mentioned that the glove box is mounted higher and does not drop down....has it been modified from factory? I do not remember if the glove box in my '95 dropped down or not. I know I did have to take the dash out and replace the vacuum actuator that controlled air flow as I was always getting AC on my feet and not out the dash vents.

Taking out the dash was not difficult, just time consuming and it helps to have another person when it comes time to lift the dash out the passenger side. Rest steering wheel on driver's seat. Just bag and label all the screws...there are several different sizes. Also a really good time to clean the inside of the instrument cluster.

Good luck.

 

i have a 2000 chevy blazer 4.3L and my temp is always just a line under 210..

 

Thank you whoever moved this I thought I put it in the wrong spot right after I posted it sorry!