Question about 1999 Chevrolet Blazer

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The a/c is blowing hot air. the clutch engages on the compressor the condensor tank gets cold. one side of the compressor is hot and the other is cold. I put a can of 134a in and there does seem to be any leaks. Is there some type of diverter valve that can be stuck in the vent under the dash board or is there a vacuum switch that could be stuck in the heat position.

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Blend door motor

Posted on Jul 30, 2008

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2007 ford KA blowing hot air


see this causes and fix it. God bless you
Compressor Checks
checkmark.gif Start with the compressor. Does it engage when you turn on the A/C?
If so, the compressor is working and the A/C system probably contains enough refrigerant to make cold air, so the problem is inside the HVAC unit. Replace the motor that controls the blend air door (this is a difficult job and best left to a professional since it involves tearing apart the HVAC unit -- about an 8 to 10 hour job!).
If the compressor does not engage when you turn on the A/C, see if it will run by jumping the compressor clutch wire directly to the battery (use a fused jumper wire). If the compressor works when you jump it, and the A/C blows cold air, the system contains refrigerant and the fault is likely a bad A/C compressor clutch relay or a bad clutch cycling switch or pressure switch.
If the compressor does not engage when you jump it, the problem is a bad compressor clutch.
If the clutch engages but the compressor does not turn (the belt will start to slip and squeal), the compressor is locked up and you need a new compressor.
If the compressor clutch engages and turns the compressor, but the A/C still does not blow cold air, the system is probably low on refrigerant and needs to be recharged.
Refrigerant Checks
checkmark.gif Connect an A/C pressure gauge to the HIGH SIDE service port (located in the high pressure hose that runs between the compressor and the condenser in the front of the engine compartment). The gauge will tell you if there is any pressure in the system. Simply depressing the service fitting valve with a small screwdriver to see if any refrigerant squirts out is NOT an accurate check because it tell you how much pressure is in the system. It may still have some pressure but not enough to trip the low pressure safety switch so the compressor will engage.
If your A/C system is low or out of refrigerant, check for leaks, then have the A/C system vacuum purged to remove air. After the air is out, it can be recharged with the specified amount of refrigerant. It is important to get any air out as this will reduce cooling efficiency and may make the compressor noisy.
A/C System Functional Checks
checkmark.gif If the refrigeration circuit seems to be working (refrigerant in the system, compressor running and building pressure), but there is still no cooling, the problem might be an obstruction in the orifice tube (located in the high pressure hose between the condenser in the front of the radiator, and the evaporator located in the passenger compartment). A blockage here will prevent the refrigerant from entering the evaporator or recirculating through the refrigeration circuit.
If the orifice tube is plugged, the high side pressure reading will be lower than normal, and the low side reading will also be lower than normal because no refrigerant is circulating through the system.
checkmark.gif If the refrigeration circuit seems to be functioning normally (compressor running, frost or condensation on the high pressure line from the condenser to the evaporator), but no cool air is blowing out of the ducts inside the car (and the blower is working), the fault is likely a BLEND AIR door that is stuck in the HEAT position, or possibly a badly clogged cabin air filter that is restricting airflow. Another possibility would be a fault in the automatic climate control system such as a ad interior temperature sensor or control module.

Sep 28, 2012 | 2007 Ford Ka 1.3

1 Answer

Arcondition blows hot air, freon in the blue and clutch on compressor engage


Make sure your blend door is closing all the way and that the actuator actually works.

Aug 23, 2012 | Cars & Trucks

1 Answer

My air conditioner is blowing warm air on the driver side and cold on the passenger side


see this steps and think with clearly and logically NOT feared. God bless you
checkmark.gif Start with the compressor. Does it engage when you turn on the A/C?
If so, the compressor is working and the A/C system probably contains enough refrigerant to make cold air, so the problem is inside the HVAC unit. Replace the motor that controls the blend air door (this is a difficult job and best left to a professional since it involves tearing apart the HVAC unit -- about an 8 to 10 hour job!).
If the compressor does not engage when you turn on the A/C, see if it will run by jumping the compressor clutch wire directly to the battery (use a fused jumper wire). If the compressor works when you jump it, and the A/C blows cold air, the system contains refrigerant and the fault is likely a bad A/C compressor clutch relay or a bad clutch cycling switch or pressure switch.
If the compressor does not engage when you jump it, the problem is a bad compressor clutch.
If the clutch engages but the compressor does not turn (the belt will start to slip and squeal), the compressor is locked up and you need a new compressor.
If the compressor clutch engages and turns the compressor, but the A/C still does not blow cold air, the system is probably low on refrigerant and needs to be recharged.

7_25_2012_8_45_21_am.jpg

Jul 24, 2012 | 2007 GMC Sierra Classic

1 Answer

05 tc. A/C blows hot then cold. Didn't blow cold


The A/C pump ismade of three seperate components. You are correct in it being electrical, to some degree. The compressor is self turnes, & in turning moves the freon thru the condensor,dryer, evaporator, & condensor. With the engine off, you can grab the clutch on the compressor, & turn it manually. Now, to your question. When you turn on your A/C, it sends a signal to one of 3 parts on your A/C compressor. The 1st signal, is a charge to the magnet (not its nomenclature name) that pulls the clutch, quickly, into the compressor shaft, so it can start turning. Now as this signal, is working,on an intermittant basis, 1 your clutch has been damaged, not always engaging fully,causing disc wear. The activating magnet, works intermittantly, this too, strains the electrical wiring, going thru the compressor to the magnet. Now the compressor works, but, 2 components, have gotten very hot, by intermittant action. To remove them, if "fused", will be labor intensive. Thanhaving a "sealed" system, dis-assembled, then re-assembled on a mechanics work table. No matter how hard I try its never completely clean......the repaired compressor can allow harmful contaminates into a system that works, with one part not working. Once contaminates are in the system......all the components can be damaged. The mechanic, is giving you the most cost efficieant repair, that will last longest, with least possiblility of failure.

Aug 31, 2011 | 2005 Scion tC

1 Answer

Location of ac high pressure cutout switch on a 97 Plymouth voyager. Could it be a different problem? Had to replaced the PCM and a couple sensors because of a short in the wiring cluster. Now the ac...


HIGH PRESSURE CUTOFF SWITCH LOCATED ON AC COMPRESSOR DISCHARGE LINE LEADING TO THE CONDENSOR.THE HIGH PRESSURE CUTOFF SWITCH WILL CUT OFF THE AC COMPRESSOR IF SYSTEM PRESSURE RISES TO HIGH CAUSED BY RESTRICTION IN THE REFRIGERANT CIRCUIT OR OVERHEATED CONDENSOR.MAKE SURE COOLING FAN IS RUNNING WHEN THE AC SWITCH IS ON.THE COOLING FAN KEEP CONDENSOR COOL, IF COOLING FAN DONT RUN.YOUR AC WILL STOP BLOWING COLD AIR.HAVE THE REFRIGERANT SYSTEM CHECK OUT.MAKE SURE YOUR LOW SIDE PRESSURE IS 10 - 37 PSI. THE HIGH SIDE PRESSURE SHOULD BE 112 - 210 PSI. CHECK THE AC COMPRESSOR CLUTCH FUSE AND RELAY.

Jul 29, 2011 | Plymouth Voyager Cars & Trucks

1 Answer

Problem with heating and air conditioning. The driver's side is blowing hot air and the passenger side is blowing cold air


Air Conditioner blows warm air
  1. Air conditioner system is discharged. Have the system evacuated, charged and leak tested by an MVAC certified technician, utilizing approved recovery/recycling equipment. Repair as necessary.
  2. Air conditioner compressor clutch not engaging. Check compressor clutch wiring, electrical connections and compressor clutch, and repair or replace as necessary.

Jun 01, 2011 | 2004 Buick Century

1 Answer

My GMC Sierra's air conditioning works great but the driver side vents will spontaneousely start blasting out hot air. The passenger side continuse to blow cold air. If iI turn the truck off and...


  1. Air conditioner system is discharged. Have the system evacuated, charged and leak tested by an MVAC certified technician, utilizing approved recovery/recycling equipment. Repair as necessary.
  2. Air conditioner compressor clutch not engaging. Check compressor clutch wiring, electrical connections and compressor clutch, and repair or replace as necessary.

May 24, 2011 | 2005 GMC Sierra

1 Answer

96 chevy blazer not blowing out cold air only 70 deg.freon full clutch engage and disengages


Have you checked the low side and high side pressures? The compressor might be bad. Does one line to the compressor get cold and the line coming out get hot?

Jul 02, 2010 | 1996 Chevrolet Blazer

1 Answer

My 2002 Expedition air conditioner will sometimes blow hot air and others cold air


I would check the following possibilities:
1. Is compressor clutch working? - You need to do this when the ac is blowing hot air only - locate compressor drive pulley on engine - rubber belt wraps around it. Start engine and set to max ac. When the ac is blowing hot air, look at the center of the compressor drive pulley using a good flash light - watch it for a while, it should be spinning with the pulley - this means the compressor is engaged. If not, the compressor is not engaged. If your ac is blowing hot air, then the compressor should be engaged and running (trying to cool). If it is not engaged, then your compressor clutch is probably going out. Could be low voltage to clutch, but more likely the clutch is worn out and only working some of the time. Note: if working normally, the compressor clutch will engage and disengage in cycles- but the air should always be cold. If clutch is bad, compressor would need to be replaced (sold as one unit). This is tricky to diagnose and could take some time - you need to do it when ac is blowing hot air but set to max cooling.

2. Low on refrigerant or refrigerant has moisture in it? If your ac blows cold initially after being off for a while, then heats up, and continues to regularly cycle back and forth between hot and cool air, then the system may be low on refrigerant or the refrigerant may have moisture in it that is freezing and restricting refrigerant flow. An a/c shop can check refrigerant level and even replace refrigerant if moisture is suspected.

Could be other issues, but I would start with these.

Good luck

May 07, 2010 | 1999 Ford Expedition

1 Answer

2005 KA blowing hot air out when set to cold


start car.turn on air conditioner high cool .raise hood look to see if the compressor clutch is engaged and running.if yes your ac air door could be stuck closed or the air door vacuum actutator not receiving vacuum.a vacuum line is broken or off. or the control switch bad.that control the AC and heater mode. if compressor clutch is not engagged.check for power at compressor clutch.if yes compressor clutch coil open. or the air conditioner refrigerant R 134 is low take car to a private garage with a good reputation. they wont be expensive as the dealership.have them hook car air conditioner to a manifold gauge set to check your refrigerant low side and high side pressure.

Jun 24, 2009 | 1999 Ford Taurus

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