Why does my blower motor run when the car is off?
Blower Motor runs when car is off! Long story short – it was the blower fan regulator. For future reference, don’t buy a cheap off brand replacement unit, it may be defective.
What to do if your AC blower is not working?
Disconnect cables to motor and resistor. Remove hose from motor, it should just pull off with little effort. Unscrew motor and resistor. Screw new motor and resistor in. Connect hose to motor. Connect cables to motor and resistor. Turn on car and test AC. Thanks for watching! Loading…
What are the symptoms of a bad blower motor relay?
3. Melted relay. Another more serious symptom of a problem with the blower motor relay is a burned or melted relay. Relays are exposed to high current loads and can sometimes get hot when they develop problems.
How long does a Mercedes Benz blower fan run?
Pressed the switch again, the blower fan stopped again for a few seconds, then resumed the lower speed. The owner’s manual notes the fan may run for up to 30 minutes in warmer temperatures. Left it for an hour – still running at the low speed.
What causes a blower motor to stop working?
In a situation where the motor doesn’t work on any speed, the most likely causes are: a blown power supply fuse, a bad motor ground connection, bad motor speed control module or a failed motor. On all systems, a failed blower motor is least likely. Blower motors generally don’t fail out of the clear blue.
What kind of motor does a variable speed blower use?
Variable speed blower motors don’t use a blower motor resistor. Instead they use a blower motor speed control or a power transistor. Variable speed motors are most often used in vehicles with automatic climate control.
3. Melted relay. Another more serious symptom of a problem with the blower motor relay is a burned or melted relay. Relays are exposed to high current loads and can sometimes get hot when they develop problems.
Where does the power go in a blower motor?
For each higher speed, power flows through one less resistor. Some car makers run blower motor power through the fan speed switch first, then through the blower motor resistor and then to the blower motor and ground. Other car makers reverse that and run power to the blower motor first and terminate ground at the blower fan speed switch.
What to do when front blower doesn’t work?
Front blowers don’t work when back ones do. AC is still cooling. Turn van off, restart and everything works again. Maybe for minutes, maybe for days or weeks. Four different mechanics and dealers have looked at the problem.
What happens to the lead in the blower when the car is off?
The three prong connection that attaches to the regulator should always have power from the red lead, the brown lead is ground, and the white/pink strip lead is controlled by the fan switch. With the car off, and the fan switch in the “off” position, there should be no power to the white/pink lead.
Why is my Mercedes Benz blower motor not working?
If there no power is found, the blower motor resister is the culprit and needs to be replaced. As a note, 85 percent of the time when the blower motor does not come on or operates at one speed only, the blower motor resister is at fault. The resister emits substantial heat from the resistance it supplies and eventually burns up.
What causes a fuse to blow on a blower motor?
If the blower motor relay develops any sort of problem that hinders its ability to properly limit and distribute power, it may cause the blower motor fuse to blow. Any sort of electrical spikes or excessive current from a bad relay will blow the fuse and cut power in order to protect the system.
Where is the blower control switch on the dashboard?
The blower control switch on the dashboard controls the circuit flow of the blower motor to adjust the voltage from low, to medium, to medium-high, to high. When on high, the circuit bypasses the blower resistor.