1994 chevy s10 blazer the temp gauge dosent move and the heater only blows luke warm air it has coolant in it and the heater core was replaced last winter and has had no issues till a couple days ago

heater blows cold air idle chrysler 300 Questions & Answers ...

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Find solutions to your heater blows cold air idle chrysler 300 question. ... blow warmair for a few mins then back to luke warm. i replaced thermostat ... HEAT BLOWSCOLD AIR WHEN IDLING ONLY GETS HOT WHEN START DRIVING ... About 15 minutes after driving the diver side vents start blowing straight cold air but the ...

Heater only works when pressing the gas? - DoItYourself.com ...

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Nov 3, 2011 - When I press the gas, the air from the vents is nice and hot. .... So am Idriving a car with a ton of problems, or could the power steering ... Just anotherquestion, when warmed up does the engine temperature ... When the heater is on and I'm not pressing the gas pedal, luke warm air blows from the vents.

Heater blows cool air when stopped and warm air while ...

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RedditFeb 12, 2014 - Heater blows cool air when stopped and warm air while driving 2008 Kia Spectra (self. ... just fine but appears to blow cool air when I was stopped at a stoplight. ... My temp gauge would also be pegged high when at idle / low RPM. ...thermostat only blocks coolant going to the radiator, and the heater core, ...Missing: 300m ‎luke

Why is My Car AC Blowing Hot Air? - BlueDevil Products

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Possible plugged heater core. Check heater hoses when engine at operating temperature. Both hoses should be close to the same temperature. If one hot and one warm/cold, suspect a plugged heater core. A backflush will be required to correct the problem if it is plugged

You need to verify that warm coolant is getting to the heater core by touching the hoses going into the firewall. If they are both the same temp or close, you might have a blend door actuator broken or sticking that does not direct warm air into cabin area

Try replacing radiator cap. I'd do this first and if that doesn't cure it replace heater control valve. The cap is the cheaper of the two.

Does the air coming out of the vents change when you move the temperature control knob? If you can't feel it, you should be able to hear the change

Is the fan turning on? I assume so.. when you change the hot/cold selector do you hear the flaps inguage? could be the linkage there. Otherwise, check your coolant level - make sure your heater core isn't plugged (let engine heat up, then see if the heather both heater hoses going into the firewall are warm). If one is colder than the other, flush the heater core.

If I understand you correctly, your temp gauge shows correct operating temperature, your blower fan blows air that you can feel with your hand from the right floor or dash outlet, but that air doesn't feel warm until you are moving?

If so, several possibilities come to mind. One is that your coolant level is low. Even though your temp gauge reads in the right range, the coolant level could be low enough that it doesn't reach the heater core until there is enough engine RPM to create more pressure from the water pump and force what coolant is there toward the heater core. Another possibility is that your heater controls are not able to do their job. A stuck flapper in the duct or a malfunction with the temperature control system could be causing the problem, and at 15-20 MPH there is enough air coming through the outside air vents to provide some heat.

I'd check the coolant level first, though. The other possibilities are more far-fetched.

It sounds like you have low engine coolant levels or air trapped in the coolant.

maybe a blockage or thermostat is in backwards

the problem is caused by the motor that operates the air temp blend door motor in the heating ducts, it blends air between AC and heater core tro give desired outlet temp.