AC only works on low speeds and shuts off Compressor on 3 and 4?
When I turn on the A/C (which is fully charged) it works on the lowest two settings/speeds ... but as soon as I turn it over to the higher speeds it shuts off the compressor and tuns on the fan ... which blast cold air for a short time until it has gone through what the A/C unit was pumping out at the very lowest settings ... The place where I bought it basically told me to go "get lost" ... they can't scan it or fix it ... I know, nice dealership ... but before I take it to some Mazda guru and get told it's a bot load of cash or get ripped off .... I was just wondering if it would be something small .. as the system works, but something tells the A/C unit to shut off on high speeds .... any help?
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Re: AC only works on low speeds and shuts off Compressor...
YOUR BLOWER MOTOR RESISTOR NEEDS TO BE REPLACED. IT IS LOCATED IN THE AIR DUCT NEAR THE BLOWER MOTOR. I BELIEVE IT HAS THREE WIRES ON THE PLUG THAT SUPPLIES POWER TO IT. REPLACE THIS AND YOUR A/C WILL WORK AT ALL SPEEDS. HOPE THIS HELPS. PLEASE KEEP ME POSTED. THANKS FOR AN HONEST RATING AND FOR USING FIX-YA. GOOD LUCK. P.S. :RESISTOR SHOULD BE UNDER 40 DOLLARS TO BUY.
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Normally you would check for voltage at the relay then the low pressure switch, then the compressor clutch. With the system charged or the low pressure switch bypassed you should have 12 volts at the clutch and ground. You can also check the clutch with an ohms meter to see if the magnet is open.
First make sure the AC system is fully charged, with a gage hooked to the low pressure side the pressure reading should be 28-32 PSI. Also take note if the AC compressor is turning off and off continuously in short bursts, the indicates a low charge and if the charge is low you have a refrigerant leak somewhere. If that is all ok and system is not low on charge you may have a defective air temperature control blend door problem, either the door is sticking due to being warped or the actuator motor is defective or both, most times both are a problem. the part is only accessed by removing the entire dash assembly.
If it has the auto air functions.On the passenger side under glovebox remove the black cover under the dash and there is a hidden fuse block with a ac fuse. Check for this a very common issue. Also if the ac is fully charged you can unplug the low pressure switch located on the accumulator( silver canister located by the relays towards the firewall) and take a wire and place between the two terminals just make sure the compressor will does come on.If the ac is turned on and you jump that switch and the compressor does turn and ac starts working then a good possibilty that the low pressure may be bad. Would check the fuse first.
The low pressure switch is located on the accumulator, and you only need to remove the connector to the low pressure switch and jumper the wire connector to by-pass the low pressure switch, however I would not recommend doing so because it is there to keep the AC compressor from being damaged due to running it low on R-134a.
If you are trying to charge the AC system you do not need to by-pass the low pressure switch, just start the vehicle and turn the AC on to maximum, then charge the AC system and when there is enough pressure in the system the compressor will come on, and then just continue to fully charge the AC system.
You should not have to do anything to charge that AC system, except to start the engine and turn on the AC to maximum, then charge the AC system, when there is enough pressure in the system the low pressure switch will trip the AC compressor on and you can continue to fully charge the AC system.
the blower motor has no affect on the AC system, start the engine and turn on AC and watch the AC compressor to see if clutch engages,if it doesn't the system isn't full,if you are correct the clutch should be engaged and should quit when you change heater speeds,
GM products have a safety feature which shuts down compressors is they run too low on refrigerant. Honestly surprised you were able to fill the system with refrigerant since the compressor would have shut off. The best way to reset the compressor is to disconnect the negative battery cable for 15 min. After reconnecting, the compressor should function again assuming there's enough R-134A in it. If there's not, turn the AC to MAX and add the refrigerant. At this point, the system should actually **** the can dry. Hope this helps with your AC problem. All the best! Greg