Need some LED Help... Custom project

[NateRW21]

Well, it's not anything crazy... and it's not even for the LS... but I know there are a couple guys here that are creative, and really good with LED's.

So here's my problem...
I've got a 3-pod A-pillar gauge set-up for my truck; running a diff temp gauge for the front, tranny temp gauge and diff temp for the rear. For the front diff and tranny I'm going to soon be setting up auxiliary oil coolers; the fluid will be pumped from the diff or the B&M aluminum pan on the tranny using a tilton electric fluid pump into an oil cooler with a fan. The pump will turn on at one temp and the fan at yet another temp. Anyhow... where the LED's come into play...

I want to know when the pumps and fans come on, so above the gauge for the front diff temp and tranny temp, I want to install mini LED's wired into the thermal switch which will turn on the pumps and fans. This way I know that the systems are functioning and it will also sort of get my attention of elevated temps.

BUT... I have no idea where I can get mini LED's that are already set-up for 12v... or, how to set up normal mini LED's to run on 12v (I know it would require a certain resistor). Also a factor is the brightness of the LED's... I don't want something that will blind me at night, but I need it to be visible during the day.

Any help you good gentleman can give would be greatly appreciated!

 

[owlman]

oznium.com has prewired 12v stuff and a pretty good selection if you want the easy route. I only bought some small things from them a long time ago but I had no problems with them.

Also you could try getting a variable resistor/pot so you can adjust the brightness for day & night!

 

[NateRW21]

Thanks owlman!

I didn't know you could adjust the brightness of LED's! SO in theory, if I could find small enough relays, I could have one resister set-up for day driving, then when I turn on my lights, the other side of the relay kicks in, using a different resistor, decreasing the brightness of the LEDs?

 

[owlman]

They don't dim as linearly as a normal lightbulb but yeah you can still adjust the brightness.

I like the idea of having it wired up to bump down the brightness when you turn on your lights!

 

[NateRW21]

Simple to do using an SPDT micro relay:
http://www.radioshack.com/product/index.jsp?productId=2062481&tab=techSpecs

Not big on radio shack junk, but... These are really really small, so they would work perfectly. Your common would be the + side of the LED with the power to the LED splitting to two resistors, one to each switched terminal; would be pretty easy really. Just have to figure out which resistors I need!

 

[joegr]

With normal LEDs, all you need is a 1.2K ohm to 10 K ohm resistor (depends on how bright you want it to be) in series with the LED. A 1/4 watt resistor is more than enough, but the 1/2 watt size maybe easier for you to deal with.

Depending on where and how you mount the LEDs, it may be possible for one brightness level to work okay both during the day and at night.

 

[1LoudLS]

you can usally find somthing like a three pack of single 12v LED's at autozone or walmart in the ricer section. they are the easiest to use in you set up, ther are simple two wire led with the resistor already inline. all you will need to do is ground one side and run the other side to the +12v wire right at the pump and fan, that way once the thermal circuit turns on either of them it will also turn on the led.

 

[1LoudLS]

you could also use one of your dash light wires to trigger a relay to run through a small extra resistor to dim the led's whenever the headlights are on