Ford F150 - LED's underdash.

I would like to install some LED's under the dashboard. Can I wire these LED's to the electrical switch for the outside driving lights? I will find the correct resistor for the LED's I want to install.

What should I do?

you could do that, I just installed mine yesterday (all homemade) but was doing several projects at once to I ran a new line and fuse box back from the battery. I had also installed secondary reverse lights and a few extra cigarette lighters for accessories. My led's switch on a switch panel in the empty slot above my aftermarket radio.

I don't see why not. When I wired LED's to my fans I just put them inline with the power cable to the fans.

I have a ford excursion 2004 V10.

Does the light switch, come out from the outside of the dashboard?

Can I pull out the housing without unscrewing anything?

In otherwords, will the housing that holds the dimmer switch, and the light switch, pull out from the dashboard?

Thanks guys, I could use the quick reply.

Well it turns out, that I will not be linking the LED's with the exterior lights.

I had the idea, of hooking the LED's directly to the car battery, including an "inline" fuse, a correct resistor, and a ground wire from inside the car.

Any comments on that?

If you hook up the LED's to the battery they will stay on all the time. They need to be on a switched circuit.

once again, i forgot to mention I was going to put in a switch.. The inline fuse is a must correct? What size inline fuse should I use?

Radioshack is the best place to get those types of things in my local area.

Thanks Simoli

5 amps would be more then enough-I only used 7.5 b/c it was the smallest one I had.

My battery is 750Amps cold cranking.

Kinda confused.

LEDs need to be current controlled. Proper current for a 5mm LED is about 20 mA (0.020 amps). If you don't current control them, they will fail prematurely.

Are you using a kit of some kind, or just putting some in?

Nick

On my excursion, i found a 12V power lead, that is comming off the Dimmer switch (for the dash lights) that only comes on when the outside lights are turned on.. The wire off that dimmer, is a brown wire. Can I use this wire to connect my LED's?

Yes, that will work for a feed, but it still should be current controlled. Is this a kit, or something of your own creation.

Nick

Yes, I will wire two sets of two LED's in series. For each set I will use 270ohm resistor 1/2watt

Sounds good?

Yeah, that should work fine. Keep an eye on the resistor temp. 1/2 watt may get hotter than you'd expect.

For those wondering how the resistance was calculted: LEDs don't have any real resistance while they're on, but they do have a voltage drop. This varies depending on color from half a volt to as high as a volt and a half. You can look this up with google.

To come up with resistance to achieve desired drive current, take supply voltage (measure, but should be between 12.5 with the truck off and 14.5 with it running) and subtract the voltage drop of the LEDs. Then apply ohmw's law: take the voltage after subtraction (10.5 for exaple), and divide by the desired drive current, say 30 mA. In this case 10.5 volts/0.03 amps=350 ohms. To find power rating, multiply current by voltage 10.5 volts*.03 amps= at least 0.315 watts.

Nick

Whats the LEDs for?? I like adding lights in the interior since I cant do it on the outside.. Show us some pics when yer done..