My heat and AC will only blow if I set it to blow out at a rate of 3 or higher. The low settings of 1 and 2 don't work. I thought I would need to buy a whole new heating/ac unit but someone told me all I need is a regulator or sensor or something. Is this true?
2007-02-09 12:03:44 · 7 answers · asked by mll804 2 in Cars & Transportation ➔ Maintenance & Repairs
The above two answers are incorrect. Assuming your vehicle has the basic manual heater-A/C, which means the mode (defrost, heat, vent etc.), temperature, and blower speed have to be set MANUALLY, it sounds like you only need to replace either the blower resistor (the most common cause of what you describe), or the the blower speed switch or connector. Usually when the resistor fails completely, the blower speed will operate only on the high setting because the full 12 volts are supplied to the blower motor circuit, bypassing the resistor completely.
2007-02-09 12:29:49 · answer #1 · answered by Michael 3 · 0⤊ 0⤋
The resistor is what allows you to select diffrent speeds for the fan. Your swith has several settings each position sends power to a diffrent prong on the resistor. The resistor has usually three wires that are coiled like a spring. Each one has a diffrent resisteance built in. Your switch position dictates what resistance wire the voltage is going through and thus dictates fan speed.
I would bet all you need is a new resistor. Easy to replace. All you need is a 5/16" socket and ratchet. The resistor is located in the air stream either outside if the Evaporator housing is under the hood or behind the glove box if it is inside. Just remove the two screws unplug the electrical conector and replace. When you pull it out you will see three to four springs on the inside. It is mounted in the ac airstream so it can be cooled. As the power flows through the wound wires it heats up because of the resistance.
2007-02-09 20:28:18 · answer #2 · answered by Can do it man 3 · 1⤊ 0⤋
The heater/AC fan is controlled by the fan switch. Each switch position except the highest position (4 or max) has a big resistor in series with the input voltage. As you select fan speeds, the switch adds more resistance as you get down to speeds 3, 2, or 1. These resistors drop voltage to make the fan run at different speeds. Sometimes the resistors burn out. It sounds like the resistors for your positions 1 and 2 are burned open. It is possible the switch itself is defective, but more likely it is two of the resistors.
2007-02-09 20:33:45 · answer #3 · answered by Phillip S 6 · 0⤊ 0⤋
Not a sensor, it's a resister block. You'll find it behind the glove box, usually mounted into the blower motor area so the air flow will dissipate the heat it puts out. Has a plug on it.
2007-02-09 20:32:12 · answer #4 · answered by oklatom 7 · 0⤊ 0⤋
there is a resistor on the heater box under the hood. usually if it is bad the fan will only blow on high. i would check the switch that controls the fan speed first.
2007-02-09 20:58:22 · answer #5 · answered by slayer 2 · 0⤊ 0⤋
No not true... no sensor controls your blower motor..... if it works on high but not the 2 lower settings, check your fuses first.
2007-02-09 20:18:52 · answer #6 · answered by Anonymous · 0⤊ 3⤋
I think it's a type of thermostat
2007-02-09 20:13:38 · answer #7 · answered by TitoBob 7 · 0⤊ 3⤋