No Heat!!??

[Hunter1]

Ok after hours of reading posts, i'm stuck. I have a 98 blazer lt auto climate control. My problem is I have no heat. The operating temp of the truck is only about 150 Degrees (I can't help but feel the two are related). I have flushed the entire cooling system. The rad. is new (unrelated repair). The fuses are good. I can hear the blender door opening and closing as it should. thanks in advance for any help...

Hunter

[BlazerBoyLT98]

Sounds like you have a stuck open thermostat, should be replaced with one that is 195 dgrees I believe. Basically the coolant is flowing freely around the engine, consider yourself lucky, if the thermostat was stuck closed you would have plenty of heat! And a possible blown engine!

[Hunter1]

Thanks I will try that!

[Hunter1]

I changed the thermostat. temp back up to 195 but I still don't have any heat from the heater. are there any other suggestions?

thanks

Hunter

[alblogg]

When you said you flushed the entire cooling system did you unhook your heater hoses from your heater core and back flush it? If not this might be your prob. or it has air trapped in it and needs burped out.

[IceFire]

I had the same issue with mine. What the problem was is the hose that goes from the heater box to the intake manifold where the metal pipe connects to the intake has a smaller diameter hole and the end of the pipe begins to wash away. Small pcs gradually wear off and end up getting stuck into the end of this pipe. What you need to do is disconnect the pipe from the intake, clean the end of it and reinstall it.

[Hunter1]

I did a back flush on the heater core, but that didn't seem to help. I am inthe dash right now. I have two vacumm hoses (one black the other orange) the black one controls the vent location but I can't figure out what the orange one controls (at least from the controls on the dash) It is attached to a vent that if I onpen it manually a rush of air leaves from inside the cab. The truck has auto temp controls which have never seemed to work right(ie outside temp is 30 and the a/c kicks on (WTF?!?!?)) The other problem is that I can't seem to find the blend motor. But I guess I will try to get back to it. Just let me know what you guys think. I will be working on it this weekend since I don't have to work.

Thanks

Hunter

[Chris Stewart]

Originally Posted by Hunter1

I did a back flush on the heater core, but that didn't seem to help. I am inthe dash right now. I have two vacumm hoses (one black the other orange) the black one controls the vent location but I can't figure out what the orange one controls (at least from the controls on the dash) It is attached to a vent that if I onpen it manually a rush of air leaves from inside the cab. The truck has auto temp controls which have never seemed to work right(ie outside temp is 30 and the a/c kicks on (WTF?!?!?)) The other problem is that I can't seem to find the blend motor. But I guess I will try to get back to it. Just let me know what you guys think. I will be working on it this weekend since I don't have to work.

Thanks

Hunter

The one that pulls air from inside the cab is the air recirculation door...during AC, it pulls cool air out and runs it past the AC evaporator instead of grabbing hot air from the outside. Cools and dries the cab air much faster and reduces the amount of condensation to deal with.