Ever since I bought my blazer the heat has been stuck on. Well... short on time last summer, I just bypassed the heater core. Now that winters is peeking it's head just around.... I'm getting ready to hook it back up. But I've always had this weird sound that kinda sounds like a frog(squeaking) in my dash somewhere. I would think it would be the cause of my heat being stuck on. But I had a friend that had an zr2 that made the same noise but his heat and a/c worked without anyproblems. My truck doesn't seem to make the noise all the time and I can't figure out anything that actually causes it to start up.

 

Sounds like the blower motor or someting caught up in it !! my 2 cents

 

maybe a frog stuck in it.... lol

 

Na... It's not the blower itself. The fan is off when it makes the sound.
And I hope it's not an actual frog in there... Must be alot of bugs back there to eat for the last 2 years.
It kinda sounds like a vacuum opersted something squeaking. My heat has been stuck on the hottest setting ever since I bought the blazer (no matter how cold it's set on the ****). So I'm betting that it's the blend door actuator making the sound. But I know my buddies ZR2 made the same noise, but his temperature changed with his ****. Either way I'm going to have to tear into the dash and fix it. It gets so hot in my blazer in the winter I still have to roll windows down.
I searched and didn't find anyone else having the weird noise.

 

Yeah a vacuum line is buggered up &/or it's causing a door not to operate properly. Or the door itself is stuck.

 

Ha, I thought the same thing when I read it. I have too much sarchasm in my diet.

 

I was going to say that the other day too

 

When you get your dash all apart...take some pictures and post them here. That way others can see what it takes to get to the heater core.

 

im planning on dedicating my day as well to opening up the dash. I hear its a mega job and takes time and patience..... good luck...