Building auxiliary LED back up lights for Jeep

[Athos76]

Hello All!

I was looking for some know-how and help on building my own LED Auxiliary back up/reverse lights to use with my Jeep. I know I can buy some standard halogen cheapies...but I like the DIY route better.

Essentially, it needs to be small and rugged.. the light output should be enough to say...light up a trailer or use as supplemental lighting while camping, and also be used in addition to the stock reverse lights.

I've looked at some Cree XP-L and Luxeon Rebels...but the idea was 2 LEDs per light (2 lights on the bumper)... one led as a spot and one as a flood.... Are there any small rectangular reflectors with spots for 2 LEDs?

A friend has access to a milling machine and CNC machine, and I'm pretty good at welding ABS plastic... I do have an electronics background...but when it comes to the design and specs of the LEDs and drivers (and reflectors) I'm at a loss... it kind of sucks that I can build an airplane and helicopter in my sleep... but get lost on a light...

Thanks in Advance

[Hilldweller]

Have you looked at the VisionX or Rigid lights?
Trucklite also makes a ton of LED worklights, back-up lights, floodlights, trailer lights, (I could go on and on...)...

[AnAppleSnail]

You are probably not able to make a road-legal reverse light. In the US there are particular optical standards that must be adhered to. Lots of cheap third-party suppliers sell kit that is illegal and unsafe to use.

Get some quality ones (Scheinfeinwermann or someone will be in soon to advise). The optical tests provide visibility, avoid glare, and allow unambiguous identification of signals - but are expensive to pass (You can build, but can you iterate the design to correct off-axis light output?). For safety and liability, use correct road lighting. For off-road lighting, specify that - and don't use 'em off-road.

[Athos76]

Sorry for the confusion... Yes this is only for offroad.
Since I go wheeling quite a bit now, backing up in total darkness with stock jeep taillights is a pain on the butt.

If I could afford a set of RI lights, I wouldn't have them as back up lights...and I like the challenge and satisfaction of building things myself.

The lights mainly need to be flood. The spot was just an idea if plausible. The light only needs to brighten up a 30 ft or so area behind the jeep.

[Hilldweller]

You are probably not able to make a road-legal reverse light. In the US there are particular optical standards that must be adhered to. Lots of cheap third-party suppliers sell kit that is illegal and unsafe to use.

True dat.
That's why I put in the Trucklite suggestion; their products are meant for use on heavily inspected and regulated vehicles.

Here's a short list:

http://www.truck-lite.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10001&storeId=10001&produ ctId=34964&langId=-1
http://www.truck-lite.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10001&storeId=10001&produ ctId=59964&langId=-1
http://www.truck-lite.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10001&storeId=10001&produ ctId=23667&langId=-1
http://www.truck-lite.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10001&storeId=10001&produ ctId=34967&langId=-1
http://www.truck-lite.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10001&storeId=10001&produ ctId=35964&langId=-1

[Echo63]

I am planning on building an offroad reverse light too - I am planning on bending up a piece of heavy plastic to fit in the removeable towbar hole - fit a small led light, similar to the rigid dually and then just plug it in to the trailer connector to get power from the trailers reverse light connectors. When I need the reverse light.

Any idea what current the trailer/reverse lighting is capable of ? I only need 10-15w so less than 2 amps draw - what do trailer lights draw ?

[Alaric Darconville]

what do trailer lights draw ?

How big is a sarnie? (Hint: It's based on what kind of sarnie, what kind of bread, the fixins, etc...)

What bulbs are installed in these trailer lights?

[Diesel_Bomber]

If you enjoy this type of thing, that's one thing. If you just want to add lights to your Jeep............. You're re-inventing the wheel. Lots of good LED options available at a reasonable price point. You will spend more on materials and a LOT more in time than it would take to just buy a ready made solution.

[M@elstrom]

Any idea what current the trailer/reverse lighting is capable of ? I only need 10-15w so less than 2 amps draw - what do trailer lights draw ?

Generally a lot of trailer harnesses I have encountered have been tapped off one side of the rear lighting array, that said I have seen a 50w flood light successfully powered via the reverse lamp circuit, naturally it dimmed significantly when the vehicle was shut down... 12w 2A should be WELL within the capabilities of the loom

[Echo63]

How big is a sarnie? (Hint: It's based on what kind of sarnie, what kind of bread, the fixins, etc...)

What bulbs are installed in these trailer lights?

I dont have a trailer - i was wondering what kind of current they draw as they are normally piggybacked onto the rear light loom

Generally a lot of trailer harnesses I have encountered have been tapped off one side of the rear lighting array, that said I have seen a 50w flood light successfully powered via the reverse lamp circuit, naturally it dimmed significantly when the vehicle was shut down... 12w 2A should be WELL within the capabilities of the loom

I had a feeling the trailer lights on my parents trailers were 20ish watts each - i should be well below that with my project

[Hamilton Felix]

After cooking a headlight switch on my old International, then cooking a very expensive combination turn signal/dimmer/wiper/washer/cruise control/hazard warning switch on my Suburban after leaving the hazard flashers running with my big trailer connected (6 additional bulbs), I decided there is a better way: Relays and a separate power source.

Actually, I'd already installed relays for the turn/brake functions on the International, and had the backup lights on a separate switch, but I still managed to overload the tail light circuit over time using the big trailer.

My last modification on the trailer included a relayed backup circuit that uses the tow vehicle's backups only for control, using the trailer's own group 27 battery (this trailer carries a winch, not just the breakaway switch for its brakes) to power the the trailer's four backup lights. That battery is on its own charging circuit whenever the trailer is connected.

Upcoming mods on my Crown Vic will include separate power circuits to the rear, and relays for Left, Right, Tail and Backup. The only additional loads on the car's factory circuitry will be the tiny operating currents for the relays. This way, my expensive Lighting Control Module won't go bonkers. Since all of the new work will be plenty heavy duty, the backup circuit will handle any auxiliary backup lights I want to add to the car, and any backup lights on a trailer.

I suggest a nice heavy duty separate circuit for auxiliary backup lights, both to carry any likely load, and also because you can easily use a simple ON-OFF-ON double throw center off switch to give you the choice of automatic operation with the vehicle's backup lights or manual operation when parked so you'll have handy work lights.

I recall a set of halogen auxiliary backup lights on my 1993 Suburban. To use them as work lights while hooking up a trailer or something, I had to turn the key on and put the vehicle in Reverse. When I set up my old International for mostly offroad use, I installed separate manual circuits for sealed beam backups in the rear bumper and sealed beam high level rear floods. These have been very handy over the years (I even have long and short range front work lights on the front end guard, the short range light's coverage including the front mounted winch).

My first effort at installing high wattage halogen backup lights on my 1996 Suburban used the "lazy shortcut" of a rear mounted relay, controlled by the factory backups and using the trailer charging circuit the power the auxiliary lights. This mistake became evident when water got into the cheap brand relay and the backup lights stayed on and drained the battery. Also, I found I really wanted that separately switched manual "work light" function.

So that's my recommendation for a Jeep, regardless of whether you use big high-drain sealed beams or very low drain LED lamps. Separate power source, relay, light control wiring going forward so the driver can select manual "work light" operation. And if those auxiliary backups don't prove good enough as work lights, you may end up adding a circuit and some high level floods.

If this was for an ordinary SUV that rarely went offroad, I'd suggest getting a Golight that plugs into the lighter socket. I've had one for years. The suction cup will stick it to most roofs and hoods. Mine is the cheaper wired remote, though they push their wireless remote control. It's been a while since I looked at www.golight.com and I see they've added a lot, LED lamps, HID lights, etc. But for a dedicated offroad Jeep, I'd stick with purpose-built floods where you need them.

[Athos76]

So... Back to my original question... Can anyone give me a heads up on how to fab my own work lights... To clarify: I know about Trucklites, RI and the others... I could buy them... I don't want to... I want to fab my own. I don't see how making a small 2-3 led work light could run $200... Can someone just point me to a write-up or link to making a 12v led work light?

[charlie_r]

Would you like something like this?



I made this using several sets of these:



Bought from an Asian supplier, mounted on a piece of 1.5mm thick aluminum. I drive them with simple LM317 regulators in constant current configuration. The faceplate holds the lenses to the LED boards.

If you want, I can step you through the build process, using however many sets you want.

[Athos76]

Would you like something like this?



I made this using several sets of these:



Bought from an Asian supplier, mounted on a piece of 1.5mm thick aluminum. I drive them with simple LM317 regulators in constant current configuration. The faceplate holds the lenses to the LED boards.

If you want, I can step you through the build process, using however many sets you want.

Charlie,
Thanks for the info. That's close to what I want to make, just not as many in one assembly. Maybe 2 sets of 2. I would greatly appreciate a build write-up or the components you used.

[charlie_r]

The triple units are from eBay seller merryday168, you will need to ask for the lenses, as they are not shown in the seller's store. If you want more that a triple unit, there are several varieties available. The LED pads on these are wired series, and for your application that shouldn't be a problem with 1W or 3W chips.

This is what you will get if you order the set, you will need to add your own chips to it:



The drivers I used are basic LM317 TO220 package, in constant current configuration. For anything above 100mA, you will need to provide heat sinking. Since these regulators are made with the metal tab tied to the output pin, they must be isolated from the LED boards, and each other. Did you know that a 1W led will actually survive for about 15 seconds driven with 1.5A? Ask me how I know....

Schematic for the driver:



Note that you are actually connecting the LEDs to the adj pin, not the output.

The value for R1 will determine your current. Formula is Iout = 1.25/Rsense.

Onsemi.com had a PDF detailing this, AND8109/D

I'll take the time to get some pics of the basic pieces, since I need to paint them anyway. I'll try to get that done for you tomorrow.

[charlie_r]

Got a few pics of the pieces, and how I put them together.

First, let me say that I don't have a machine shop. I used basic hand and power tools to make the mount plates.

I had some scrap 1.5mm aluminum flat sitting around, so used what I had on hand.

The shaping was done with a jigsaw and belt sander, after deciding how many light units I wanted on the bar. Headlamps, 4 sets high and low beams, sort of; Turn signals; and a strobe in the center; for a total of 7 units.

First pic is the base plate, with all the screw and lens tab holes drilled and tapped to 4-40.



Since this is done with basic tools, accuracy isn't great.

The clamping plate is essentially the same, with large holes filed out just large enough to hold the edges of the lenses for the units.



Here I have 2 of the units mounted to the base plate.



Lenses are just set on top of the MCPCBs, not glued down in case I mess up and blow the LEDs.

Next, I add the clamping plate, with screws in 3 of the 4 places. The 4th screw goes into the mounting bar on my trike.



Side view, showing the overall thickness.



When I get this ready to be mounted back on the trike, it will be partially enclosed with thin sheet metal.

In case you are wondering, no, it is not going to be entirely weather tight. I have learned over the years that you either go for total enclosure and hope water doesn't get in, or you leave it open enough for any water that does get in to drain/evaporate. I have not had a problem with corrosion on the latter method.

Not the best, but I'm cheap. Blame it on my Scot-Irish ancestry.......

When I have it all mounted back on the trike, I will try to get some beam shots. But I will say this: I can see quite well at night, and with just the strobe running during the day, cars give me plenty of room. As far as throw is concerned, My yard is about 100ft (~30 metres) long by 60ft (~20 metres) wide, and it lights up the whole area quite bright with only the low beams without a lot of foreground washout. With the high beams added, I do get some washout, with a greater amount of light on everything.

Feel free to modify the design, but please post what you do. I may want to make some upgrades, to make it better.

As to the legality of this: as the trike is an HPV, no legal standards exist for use on public roads.