The blower resistor and wiring is right there next to the blower and may be what is smoking. I recommend checking the blower wiring and check resistor and wiring to see if something is shorted out.
Prolonged use or blocked airflow can cause the electric motor to overheat. This often results in smoke or a burning smell, especially if internal components like bearings are under strain. Steps to troubleshoot and fix: Turn off the blower, unplug it, and allow it to cool completely before handling.
Overheating. Blowers with worn-out parts are more prone to overheating. This can damage other components in the system, and it can even be a fire hazard if it's not addressed.
If you recieved a burning smell, this is highly likely that the resistor burnt up, or the blower motor itself.
Some of the reasons a blower motor might fail are overheating, and excessive moisture. When dust, dirt, and debris build up, it can cause the windings and bearings to burn up more quickly.
Your blower motor may show these signs when it starts to overheat: A hot or burning smell as your units operate. It is usually followed by the complete furnace shut-off. Loud humming noise and other odd sounds.
Strange Rattling, Clanking, or Screeching
One of the first signs you may notice when there's an issue with the blower motor is a strange noise coming from the indoor unit or air handler. Different noises will indicate different problems.
Cars are designed with a variety of electrical elements, including the battery and alternator. If your car smells like burning electrical or like it's burning under the hood, this could be the cause. If the check engine light comes on while it smells like burning, the spark plugs could be the problem.
A defective ground wire or ground wire connection and an open circuit in the power-side circuit (including the fuse, wiring, and fan switch) are the most common reasons why a blower motor fails.
Blower motors are designed to last just as long as your furnace itself, anywhere from 10 to 20 years. Just as with any HVAC system, the better maintained and serviced your equipment is by experienced HVAC technicians the longer it will last and the fewer repairs you'll face.
Faulty Blower Motor
If your blower motor is experiencing some issues, you may hear a high-pitched squeal or whistling sound. You may also experience rattling and loud screeching noises. The motor blower pushes warm air out of the furnace through the ducts into your home.
If the power supply voltage of the blower motor is unstable, it will lead to unstable operation of the motor and generate a lot of heat, resulting in motor heating. At this time you need to check whether the power supply voltage is stable, if it is not stable, you need to adjust or replace the power supply.
Smoke often leaves car engines as a result of overheating. This can be caused by faulty wire casings, heated residues on the engine block and overheated liquids including oil, transmission fluid and brake fluid. There may also be a fault in your coolant system, or your engine may not have enough lubricant.
When the airflow is restricted, the furnace must work overtime to heat your home, leading to overheating. In severe cases, the excessive strain on the furnace can cause the blower motor to catch fire. This risk is exacerbated if the furnace continues to run with a blocked filter for an extended period.
White Smoke
It usually means that coolant is being burned in the engine, which means that something is drastically wrong. The most common cause of this is a blown head gasket, which can quickly lead to an overheating engine.
There are several things that could cause a blower fan to burn out, and most of them are related to wear and tear on the component. Causes of blower fan burnout include: Windings that have deteriorated. Bearings that have seized after running out of oil.
Replacing a furnace blower motor costs $560, on average. Depending on the size and type of motor, most people pay $300 to $900. The average blower motor replacement cost is $560, but the final price depends on labor fees, as well as the cost of the parts.
On some platforms, a faulty blower motor relay will cause the blower not to work at all, which means there will be no airflow from the A/C. On others, the blower won't work on “high blow” but all the other speeds will work. The blower motor relay fails because it regularly deals with high current loads.
The cooling system is full of hoses that can develop leaks, allowing coolant to drip onto hot engine components. When this happens, you may notice a burning rubber smell that is especially noticeable at the end of a long journey. Coolant that leaks inside the engine can also cause white smoke from the exhaust.
An electrical fire smell is often described as a “burning plastic” smell.
Burning oil smell: As your engine oil begins to burn, it is said to carry a sulfur-like smell. Other drivers describe this smell as similar to burning fuel.
SMOKE OR SMELL WHEN DRIVING
A burned blower motor cannot exactly damage your car but you are not sure that the smoke is coming from the blower motor. Such signs indicate damage and you must tow it to a mechanic before turning the engine back on.