Using a LED for 12V Tractor

letterman · 2008-09-02T09:42:39+00:00

I have a farm tractor with a 12Volt battery (like in a car). I regularly forget to turn off the power switch when the tractor runs out of gas, or powers down under load. It only takes a few hours and the battery is dead. I've decided that I need a power indicator light to remind me that the switch is on. To use the least amount of power and eliminate having to replace bulbs, I want a LED indicator. I was looking on the Radio Shack website and this looks like what I want. My question is this: I know a LED requires a resistor. It says this is rated at 12V, but then it says it contains a LED (does not mention a resistor). I was hoping for a complete unit with the resistor built in, but it appears they do not sell them. I can add a resistor, but what size (ohms) do I need? Thanks LM

Sep 02, 2008 22 Replies

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Dave M 17 years ago

Back to the Sonalert issue that came up on this thread a few days ago. I was browsing the BG Micro web site just now and came across a couple of the panel mount Sonalerts for less than $3.00 US each. Both will operate on 12 volts; one emits a continuous tone, the other pulsates.

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Dave M Never take a laxative and a sleeping pill at the same time!!

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bruce2bowser 7 years ago

I've seen more and more LED headlights out on the road with 18-wheelers. Its like several LED bulbs are packaged into each separate headlight.

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Terry Schwartz 7 years ago

Maybe things have changed in the last 11 years.

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