AC comes on and snowflake shows when I turn on the heat
I Have a 1997 Jeep Grand Cherokee. I went to put the heat on, as soon as I turn the knob, the AC snowflake shows on the display. I pushed in the AC button to turn off the AC snowflake, turned up the heat to High once the car was warmed up, and the blower come out with cold air. I turned off the the heat all together to start over. I turned the heat dial on and once again, the snowflake came on as if the AC was on automatically. Not sure if the AC is actually on because its cold outside or if the snowflake comes on because its so cold?
My question is what could cause this.
The temp dial gauge reads that its warm, the heater coil near the floor is warm but the air blows cool regardless of how long the car has been running. And if you turn it off and on, the snowflake shows in the display until you put the AC button in to turn it off
does all of your settings for blower speeds work? have seen the blower resistor short the harness/melt the wires and cause a back feed before resulting in the a/c coming on randomly.
The settings work for all speeds and air comes out of all vents. Could this have to do with a fuse?
if you are turning on the basic defog most cars will auto turn on the ac system to have a ballanced defog on your window. but i would check the blower resistor first, then check your antifreeze and make sure its topped up and flowing.
You are describing a broken or jambed blend door as far as no heat, the A/C will run in the defrost position.
But all vents work and all vents blow air - high - medium - low. Would all of the settings still work if this were the problem and if this is the problem, is it an easy fix?
Not really the dash will have to be removed to gain access to the heater box and then the blend door.
Yes but if it were a blend door would air come out all vents? The air vent controls all work, it just comes out cold
Yes a blend door is what varies the temp of the air flowing into the heater box, if you want cooler it opens more path to the fresh air or A/C side, warmer air closes off the fresh air or A/C side, If you have the fully automatic unit there are servo motors that run the doors, if not then they are controlled by vacuum motors with a main cable controlling the heat.
I'll check that out and get back to you
your vech should have auto temp control, beings it is a limited. Does heater ever get hot? If not, does eng. get to operating temp? around 210. Is vehc low on coolant? Ck to see if both heater hoses are same temp. If not, heater core is clogged. If they both are same temp,(hot) Ck to see if the blend air door motor moves. The motor is located on bottom of a/c case, inside vehc. on pass side. Feel the bottom of the blend air motor,there is a round protrusion that you can feel move when you change the temp knob. There are marks on bottom to use as referance. If I remember correctly. the slot in part that rotates should stay within the marks. If motor only moves just a little, you need to remove the motor and try to move door by hand. If it gets hot then, you may have an accuator problem or control head issue. The snow flake comes on automatically .A/C . This is just to dehumidify the air.
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