Heater Help

[lowho75]

I have a 1998 -4 door- two wheel drive- blazer that the heat does not work? I have changed the thermostat. The heat core is not leaking. The truck does not overheat so I assume the water pump is doing its job. No leaks in the engine bay. When you turn the heat on dial number, to any number speed, dial turned to red, and last dail turned to mixed(floor and vents)nothing. Just cool air. Even on defrost. Don't know where to go form here. thanks for any help.

[ls1s10onair]

grab the 2 hoses going to the heater core? are they hot? if one is hot, and the other isnt so hot.... ur heater core is clogged....
if they are both hot, then ur problem is with the climate control system

[shaynel18]

where is the heater core located, and wheres the thermostat at, i got the same prob and need it fixed asap to cold round here for no heat, thanks

[Yogi]

Quote: Originally Posted by shaynel18

where is the heater core located, and wheres the thermostat at, i got the same prob and need it fixed asap to cold round here for no heat, thanks

The heater core is located under the dash inside the heater/AC housing, but the pipes for the heater core come out of the firewall on the passenger side of the engine compartment. T-stat is located on the intake manifold where the upper radiator hose is attached. You take off the radiator hose and the elbow that it attaches to and the t-stat sits there, inside the manifold.

[shaynel18]

so does that mean i gotta take apart the the dash to get to the heater core?

[lowho75]

Yes if you have a second gen you have to take out the dash and then you have to take out the whole heater/ac unit and there is a little cover with to screws on top and take that off and it inside. There are three hard screws you can't really see. One is inside the air box. two at the very bottom of the box where there is some heat shielding and on the fire wall. they will have you puzzled until you find them and take them out because you will not get the unit out with out getting those out. Let me know if you get stuck did both of my 2 gen blazers.

[shaynel18]

you got pics of this at all, ima try it in the am cause i did the thermostat and still got no heat, the truck normaly runs around 150dg and now its in the middle at like 200deg if not alittle over, could this be the heater coil, i socked the thermostat and brushed it off with a tooth brush and still nothin so idt its that

[myxtremetoyz]

my brothers 01 S10 did the same thing I back flushed the core and he had heat did that last year and still works great

[Yogi]

Click here for a sticky from the second gen S10 section.

[shaynel18]

how do you do a backflush??

[shaynel18]

some of the guys on that sticky sed they had leaks i dont have anything leaking, could it still be my heater core, and wow i didnt think it was that big of a job to do this, i thought maby 2 hrs b4 work id have time nope, ima hafta wait till my days off and gut the thing huh, this sux luckyly 2day is really nice so ill just jump on the bike and go to work on that

[Yogi]

Quote: Originally Posted by shaynel18

how do you do a backflush??

In normal flow the hot water comes from a port on the intake manifold, and the colder return water goes to either the radiator or the water pump. Leave both hoses connected at the heater and disconnect the other end of each hose. Hook up a garden hose to the return line and turn on the water. Let the water flush backwards through the heater core for about 5 minutes. Turn off water and reconnect hoses. Top off coolant and you are set.

[shaynel18]

thanks ima go try it right now, hopfully this works

[shaynel18]

i couldnt get the hose to the engine block off, any ideas, i pulled and pulled nothin budged, i got the off the water pump off but dats it,

[Vash]

I work on old cars a lot as a hobby. Always have my trusty cheap imported steak knife in my tool collection. It's one of those flex knifes with serrations.

On my blazer I had to cut a couple inches of baked on hose. I use the hose grease from Autozone when I reassemble.

[shaynel18]

so what just cut it off, and just make it refit?? i got sum wd40 i was just gonna spray to put it back on would that be fine

[Yogi]

Quote: Originally Posted by shaynel18

so what just cut it off, and just make it refit?? i got sum wd40 i was just gonna spray to put it back on would that be fine

Yep.

[shaynel18]

ok kool thanks i got it off and flushed, it havnt tried to see if you got heat now tho, its been warm out 2day so ill try out the heater latter and let you guys kno how it went, and if that didnt work then i guess saterday ill hafta gut the thing and try to locate this heater coil, looks like a hard job but i want my heat so ill hafta make time and deff get a 30 of sum beers for it lol

[shaynel18]

So Yea The Flushing Didnt Help Im Still Getn Hot Temp On My Dash And No Heat Threw The Vents, Im Goin Crazy

[Yogi]

Are both hoses hot when the motor gets up to temp.?

[shaynel18]

i didnt try that im about to go get my check from work so when i get there ill pop the hood and feel them

[shaynel18]

i got it to work prob fixed yeshhhhhhhhhh, thanks guys for the help

[Yogi]

Quote: Originally Posted by shaynel18

i got it to work prob fixed yeshhhhhhhhhh, thanks guys for the help

So what did you do?

[shaynel18]

idk lol, i did the flush and it didnt work then when i went to get the pay check i felt the hoses and they were btoh hot then when i got home the heat was working just fine, so idk what it was

[Yogi]

Congrats!

[shaynel18]

thanks, but it figs that now i fixed it its been like 60+ n when it was busted it was 20 outside