Switch question for rear defroster
JC Whitney sells those. Not sure if the motor pulls enough amps to lower the voltage to make a difference. bUT a ballest resistor creates heat to drop voltage. Not hot enough to damage but I’m going to try that route first before since I have 1/2 dozen in the shop. Thank you for the Info. Different way to look at it.
Joe
LOL the resistor does not drop voltage by creating heat, unless you simply mis-stated. Heat is "the effect" from the current through it. All resistors work similar, Again, "ohm's law." CURRENT is what causes voltage drop. If you take a given resistor and draw very little current (a small lamp, etc) you will get very little voltage drop. A resistor with NO load other than a multimeter .........which draws a tiny amount of current will give you zero measurable voltage drop. A larger lamp or motor, etc will give more.
Heat is a side effect. The energy........that is the voltage drop.......must be converted into something, it simply cannot disappear, so the resistor radiates heat caused by the current through it.
But there ARE differences, which is why ignition resistors for Mopars are called a BALLAST. A ballast resistor CHANGES resistance with the amount of current going through it. Some resistors have more of an effect due to temperature than others, all resistors pretty much do change resistance with current, but a ballast does this by design.
As the current "tries" (and does) rise through a ballast, it heats up, which causes it to try to flow LESS current, thus attempting to "average out" current flow
