So this one gets electric again. If girlfriend compressor turns on and the short side pipe going right into the firewall of the engine compartment is gaining cold (around 30-40 degrees), and also you space not acquiring the very same temperature air the end of the dash vents, climate you have actually a vent, ducting, or fan problem.

If you have air flow, but it is not cold, check the mix door for procedure first. There are a variety of “doors” that straight the airflow of your HVAC system.

BLEND DOOR: Directs the flow of the hot and cold air.MODE DOOR: Directs the direction the air, i.e., defroster, dash vents, floor vents, etc.RECIRC DOOR: Directs the new air in or recirculating the cabin air

These are managed by digital actuators that as soon as commanded, rotate the door to straight the preferred air flow combination. If girlfriend have ever before heard a soft knocking noise coming from under your dash, the was likely one that the air door actuators. These have the right to fail ~ above the mechanically side and electrically. See photo below. You can shot listening under the dash within of the auto for any noise when transforming the regulate from hot to cold. You will need a diagram of components location and a wiring diagram come perform trial and error on this actuators. The blend door actuator is many of the time at least easily accessible for testing, however sometimes removal of the dash is essential for replacement. Usage a check light or strength probe and verify the the appropriate signal is being obtained to the actuator based upon your wiring diagram.


If girlfriend are obtaining no air flow at all, or low air flow, you may have actually an problem with your pan circuit. An initial thing is first, check your cabin waiting filter if equipped. Make certain that the is no clogged, or has come apart and lodged itself in the fan assembly. Change cabin filter and clean pan from debris together required.

The fan circuit for most cars is pretty right forward. Your controller sends a signal (power or ground) through a resistor, then with a relay, and then to your pan motor. A many newer cars, especially those with any kind of kind of automatic air settings, these signals go v a computer also. We will be using the right forward system as an instance here. Check out the chart below.


Find the Heater & AC Controller in the center of the diagram. Look in ~ the blower switch. Together you turn the switch from low to high settings, strength is sent to the resistor unit. Because that every rate step up, the power signal goes v one much less resistor within the unit, hence supplying an ext voltage to the fan motor to revolve it faster. Notification that complete speed bypasses the resistor all together and triggers the relay come supply full 12V come the pan motor. Complete 12V and full floor will provide you the max rate the fan deserve to go.

Start by testing all fuses that are related to you HVAC system. Because that testing, you will desire to gain accessibility to the fan motor plug and the resistor plug connectors. Most vehicles, this is located directly under the passenger side dash or behind the glove box. If the fan functions on high rate only, then you know that you have a bad resistor. You will desire to make sure that the connector hasn’t charred out together well. Replace resistor and connector together needed. If no rate works, friend can check the power and also ground to the pan motor. If power and also ground are present, change the fan and connector together needed. If you have ground, but no power, you can supply strength to the power side that the plug and also make sure that the fan turns on. If the doesn’t, girlfriend will need a brand-new fan motor, yet you require to continue testing the resistor and also controller. Check for her signal to your resistor. Look at the resistor in the diagram above. In this example, friend will should test each wire for a power signal v a voltmeter or strength probe. You will be trial and error for voltage at every of the input wires. In this example, friend will acquire a complete 12V at every wire when that speed is selected from the controller if the controller is working. Test the BRN wire first on the shortest speed. Relocate to the TAN wire and also the following speed setup on the controller. Execute this test v the staying speeds and wires. If friend are gaining the signal at each input wire to the resistor, yet no voltage out, then you will also need to replace the resistor. Always, check connectors when replacing these items.

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That is not unusual to find burned or deformed connectors once resistor or engine failure has occurred.