Truck Rack Lighting

Hello,

I'm trying to plan out my first project using LED strip lighting, and I would really value the forum's input. I'm essentially trying to make a truck rack that has LED strips on the underside, so they'll illuminate the bed. The truck rack would be shaped like this, and I'm planning on making it (the rack, that is) out of steel tubing; the tubing on the rearmost crossbar and the bottom bars on the sides (from rear to cab) will be made out of slotted tubing, so as to protect the strips.

So the way I've figured it, I should be looking for an IP65 rated task-light with 300-450 lumens per foot, color temp around 5500K, as high a CRI as I can find, and preferably dimmable. That is from my limited experience and knowledge as a burgeoning flashaholic, so if I'm wrong, please tell me! I have found these strips and am specifically looking at the fifth one with the IP65 rating (SKU: IP65-UB-CRI-NW-12V), it seems to come closest of anything I can find to meeting what I think I need.

In addition to figuring out what strip I want to use, I've gotta figure out how I'm going to power it and control it: I think hooking it up to the battery would be easiest, and using one (or more) of these dimmer/controllers. Right now, I'm envisioning using one dimmer for all three sides, and running both sides in parallel (kinda like this picture). So, the way I see it, I'd run the supply wiring from the battery to the dimmer, which would be mounted in the center of the rear crossbar; from there, after the dimmer, there would be parallel wiring running from the dimmer to the left and right strips. I don't think I would need to use a driver (as my power supply would be 12v DC), although I don't know if it would be still recommended to use a driver to prevent current fluctuations. Also, seeing as how the manufacturer recommends a heat sink for the strips, would the metal tube itself work for that? (Plus it'll be used outdoors, which means there will be more airflow than cabinet lighting or some such, right?)


What do y'all think? I would really appreciate feedback. Thank you!

I've not done automotive lighting, so take whatever I have to say with a grain of salt if you want.

I should be looking for an IP65 rated task-light with 300-450 lumens per foot, color temp around 5500K, as high a CRI as I can find, and preferably dimmable.

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300-450 lumens/foot is really bright. I have 250 lumen/foot for undercabinet lighting in a kitchen, and that's more than enough for task lighting like that. Just a rough calculation for a truck bed gives a minimum of about 6000 lumens. That's about four 100W light bulbs in the area of a truck bed. That's really bright. That's not to say that it wouldn't be fine, just that this would probably end up being much brighter than you expect it to be, and you're going to be paying for higher lumens.

5500k is going to come off as very blue for most uses. I don't know if that's what you're going for or not, just thought I'd point that out. CRI for this kind of lighting shouldn't matter. Unless you're matching paint swatches in the back of your truck, you're not going to notice a difference and you're going to spend a lot more for it.

I'd run the supply wiring from the battery to the dimmer, which would be mounted in the center of the rear crossbar

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Is this dimmer weather rated? I don't see anything indicating as much. If may be better to go with something like this, where you can easily put the dimmer in a protective housing and then use a remote to do what you want. I'm sure you could find a weather-rated dimmer as well. I'd say this is the most important part and the one you shouldn't skimp on: The last thing you want is your lights randomly turning on while you're driving on a rainy night, distracting a driver and causing an accident, and then you being found liable for it.

I don't think I would need to use a driver (as my power supply would be 12v DC), although I don't know if it would be still recommended to use a driver to prevent current fluctuations.

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You shouldn't need a driver. These dimmers can take up to 24V, and voltage spikes should be well under that. I'd put a fuse in series though.

would the metal tube itself work for that?

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Yeah, the tubing should be more than enough for heatsinking. You're looking at about 4-8W/foot in the worst case, and that's nothing for that size tubing.

Overall it should work pretty well. I think you've covered most everything pretty well.

This thread needs to be moved to the automotive board.

CoveAxe, thanks for the detailed reply!

Good points on the color temp and CRI: the LED strip I chose has a color temp of between 4000k and 4500k, so it will be a little more red, good call. The reason I want (not need) high CRI LEDs is that ever since getting my HDS (which has a high CRI emitter) I've been addicted to that light; it is purely a case of want, not need ... but I'm willing to pay for it.

Regarding the brightness, you're right, that many lumens IS a lot of light in a fairly small space. However, I want to be able to set the lights to provide area illumination around the truck (I should have made that clear in my first post); that's why the dimmer is really important, because it will allow me to tailor the amount of light to the situation.

Speaking of the dimmer, that remote one looks great! Thanks! That also would let me turn the light on from inside the cab, brighten it from a workstation nearby, etc.

You mentioned a fuse, and I'm glad you did. I am just a fledgling electrician, but from my rough math I think I would be best served by 12 AWG wire with a 15Amp fuse: does that sound reasonable to you? I would like to make it as robust as possible, so if a larger gauge of wire would be better (or any other change) I'll do that. (I figure about 20 feet of supply wire before the two LED strips, which would be wired in parallel; the two strips would be about 10 feet long each. I'd wire the fuse in just before the dimmer, and split right after the dimmer.)

Lightdoctor: I placed this in fixed lighting, vice automotive, because it is basically a fixed lighting setup mounted to a car. I.e. I could remove the truck rack and disconnect the supply wiring (which I plan on having a junction in just for this purpose), put it in the garage, and plug it in to a power source, it would work just as well.

I think I would be best served by 12 AWG wire with a 15Amp fuse: does that sound reasonable to you?

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Should be. I'm not an electrician though, so you should double check. As for the fuse, I'm not sure what your current limit is for your circuit. My general rule in electronics is to make the fuse rated 50-100% more than the current I expect to see in the circuit. It's just there to prevent a fire. I don't want it to blow for any transient currents.