If your vehicle is showing burning electrical smell coming from behind the dashboard, here are the most likely causes and the parts you'll need to fix each one.
The blower motor resistor controls your cabin fan speeds and naturally generates heat. If it fails, or if the blower motor draws too much power, the resistor and its plastic wiring connector can melt, causing a strong electrical burning smell.
Improperly installed aftermarket stereos, alarms, or remote starters often have poorly crimped wires or bypassed fuses. These wires can rub against metal dash brackets, shorting out and melting the wire insulation.
As the blower motor ages, its internal bearings wear out, causing it to struggle and draw excessive electrical current. This overloads the wiring circuit behind the dash and literally bakes the wire insulation.
Over time, the electrical contacts inside the ignition switch can wear out and build up electrical resistance. This generates excessive heat that melts the plastic switch housing and surrounding wires while the vehicle is running.
Switches that handle high-current lighting circuits can suffer from internal arcing as their internal contacts degrade. This melts the switch housing and produces a distinct burning plastic and ozone smell when the lights are on.