What causes a blower motor to only work on high?
Most car manufacturers use a series of resistors to make the heater blower motor run at different speeds. And when one or more of these resistors burn out, you’re usually left with only one heater blower motor speed—high. The resistor module is easy and inexpensive to replace.
Why does my blower motor only work on low?
When a blower resistor fails, the highest fan speed usually is the only one that still works because it essentially bypasses the resistor and receives the maximum amount of voltage. When the resistor is working, it reduces the amount of voltage going to the lower fan speeds so the fan runs slower.
What are the symptoms of a bad resistor?
Usually a bad or failing blower motor resistor will produce a few symptoms that can alert the driver of a potential issue.
- Blower motor stuck on one speed.
- Blower motor does not work on certain settings.
- No air from the vehicle’s vents.
What causes blower motor resistor failure?
In most cases, a blower motor resistor fails due to corrosion or overheating. Sometimes, the mechanical resistance to the motor rotation causes an excessive electric current that can overheat and prematurely damage the blower motor resistor.
How do you test a blower relay?
Connect a test light or multimeter to the ground (black lead). Turn the ignition key to the on position (engine off), and remove the relay. Using the probe, test all terminal sockets in the relay connector. Two of the four should have power.
Why is my heater blower blowing on Level 4?
Hi I got a problem with my car the heater blower start to blow on level 4 what can be a problem More sharing options… 8 months later… but but but, what causes it to blow is often a stiff heater fan motor. It is common for it to fail again if a stiff heater fan motor is not fixed.
Why does my heater fan keep blowing out?
but but but, what causes it to blow is often a stiff heater fan motor. It is common for it to fail again if a stiff heater fan motor is not fixed.
Are the screws on the heater motor black plastic?
Yeah that thing did my head in lol, screws were indeed black plastic ones and it was even harder getting the back in as a pose to out but can confirm until now, the heater is fine so far so I assume as this point it was just the resister pack and not the motor being stiff thankfully. Lord knows how much that’ll cost…