It could be a resistor, because the D3 doesn't need the full 12 volts from the reverse light wire to tell that it's on?
doesn't the resistor limit current not voltage?
Same shit.
Ummm no?
VOLTAGE
Voltage is the potential difference between two points.
Think of it as the equivalent of water pressure.
You get voltage across something, not through it.
Voltage is measured in volts. Obvious.
Voltage causes sparks and hair standing on end.
CURRENT
Current is the number of electrons flowing per unit time.
Think of it as the equivalent of water flow rate.
You get current through something, not across it.
Current is measured in amps, short for ampères.
Despite the above, it is not correct to refer to current as amperage.
Current causes fire and death.
Just like people think High Voltage will kill you... WRONG, High Current will kill you, they usually run side by side. I work in Show Production with high current three phase disconnects, the other day I was in an arena with 1600amps per leg... thats a lot of power for one show..
Anyways, why your DMM only showed a number is because its a resistor, and the BEEP is for "DIODES" for oneway flow, also used to test connectivity
But you do use a resistor to lower voltage (or you can, because it resists the current which inturn lowers the voltage) just an FYI 330ohm will take 12v to aprox 30ohms - 3volts