Load resistor dimming

Hello, I have a 12v 27w led flood light and I would like to dim it. Can I use a load resistor to dim it a 1/4 of the original power?

You won't know unless you try. However, if it's an LED bulb, it probably won't work- they usually have a pretty flexible voltage range (like 6-24v) and you won't really be able to tell a difference in brightness. Did it come with any specs on the box, etc.?

If you have an identical light, maybe you could try wiring them in series and see if it meets your needs.

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My ex once told me I have a perfect face for radio.

It is 12v, 27w, and 2.25a.

I don't think this will work, otherwise your light would have a voltage range listed somewhere.

Your best option to try would still be to connect another one in series. However, if you want to use a resistor, a little math gives you roughly 5 1/3 ohms. If you try a power resistor of roughly this amount, that would give you one quarter the power. If you choose to do this, I'd use a 10 watt rating or more, just to be safe- it will get hot!

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My ex once told me I have a perfect face for radio.

I do remember it was a 6-24v range.

If the led has active voltage regulation you cant dim it if the regulation shuts down at a set voltage ie 6 volts. As you would need to go below 6 volt to achieve any dimming in most cases. (2) 3v leds would need 6 volts and voltage regulation reduces voltage above 6 volts up to 24 volts down to 6 volts.

Before, I have put a dimmer and it dimmed it significantly.

It depends on the regulation design, if it has no low or a lower cut off then max operating voltage on the led side then yes you can dim to the lowest voltage of led threshold of operation or regulation.

I have two high powered LEDs running through resistors on my car.

I found the value by buying a 100ohm potentiometer first and twisting the dial till I liked the brightness (if this light gets used while the vehicle is not running I would make sure the vehicle is off for the test as the extra 1.5 - 2.0v could throw everything out of whack). Then I used a multimeter (set to ohms) to find the value of resistance on the potentiometer. Even if you didn't own a multimeter... You could still buy all of those 3 things for 6 or so dollars off ebay. Too easy really!
Then you just have to make sure the resistor you buy is 3W rated +

Good luck

Forgot to mention... From what I have read, the most legit way of dimming a led is with a Pulse Width Modulator. Another way to go if you don't want to mess around with the above mentioned stuff and would also like to have the functionality of a constantly adjustable light. Also cheap as chips on ebay... Not sure about the quality, but only one way to know!
I personally wanted to "set it and forget it", but each application is different, so up to you!