I just picked up some cheap ($9 at Harbor Freight) 55w halogen driving lights. I'd like to install them under the rear of my truck somewhere to add some light to the dim, two candlepower backup lights my '96 Ram came with.

Can I just wire them to the existing backup light harness, or will that wiring be inadequate to power them?

Should I run wire to the battery and use a toggle switch?

Any suggestions/ideas would be appreciated.

Thanks.

 

Um..........

 

I have a set wired into the reverse light wiring for a couple of years now and no problems.

http://store.summitracing.com/partde...5&autoview=sku

http://www.jcwhitney.com/autoparts/P...010073/c-10614

http://www.autozone.com/servlet/UiBr...meters=Back+Up

 

If you have those wired directly into the reverse wiring, then I guess you're the luckiest SOB there is. I personally think it's too much for the circuit.

It's a good idea though, to relay that much extra current.


Good luck.

 

i have a toggle so mine can come on "by accident" when the idiot with his brights on is riding my _ _ _

 

Thanks.
DieselDemon, I think the relay would be the way to go. I can just activate the relay with the wire to the existing b/u lights, right? I had thought about doing it this way, and since I'll be moving the battery to the rear, it should be simple to run the wiring. I can just tie in to the + battery cable, right? I have done some wire crimping, trailer lights, etc. I like to use "liquid electrical tape" over the connectors.

Where's a good place to buy a relay, and are they rated for different loads?

Aperture, I've thought about that, but illegal, potentially dangerous, and with my luck the idiot would be a cop!

 

Chopper1, thanks for the links. It looks like those kits do have relays included. They appear to be kits that you wire directly to your b/u lights, with everything you need to do it right.

 

That is a really good idea, a friend of mine had a lifted truck with a set of those wired in like that under the bumper. Made loading the boat in the dark a breeze.

 

i had my lights wored right into my backup light wire for years with no problems.

 

My advice, and that's all it is....... Go to Autozone and get any relay they sell. ( you know the type. Black, square, 12 volt, 30 amp rating, 5 terminals on the bottom). The are usually Bosch, Pilot, etc. Get a 10 gauge wire WITH FUSE, from the battery, all the way back to the drivers side tail lamp. If you want to be able to activate the lights manually as well, then run a 10 gauge wire, with a 16 gauge chaser wire right next to it. Personally, I always run an equivelant size ground wire as well.(you can make a ground post at the rear of the truck.) Try to get down to frame metal for a ground. Find an exsisting hole, wirebrush it spotless, and use that as a ground post.(use a nut and bolt for a post, then use eyelet terminals to hook the grounds to the bolt). After all the gounds are attached (relay, left and right aux light), then simply spray the area with anti corrosion spray. You can even coat it with spray paint. Anything will help retard corrosion.


The reason I suggest grounding the relay to the frame is because it is one less wire you have to tap into on the factory harness.


So you have a 10 gauged FUSED wire from the battery.

1. Attach that 10 ga POSITIVE to # 30 on the relay. (Make sure the fuse is removed for now.)

2. Take BOTH positive wires, one from each aux lamp, crimp them together, and attach them to # 87 on the relay. (Some relays have 87&87a) Just use 87.


3. Run a ground wire from # 86, to the ground on the frame. The shiny, bare metal, frame ground.lol.

4. Now you must tap into the POS wire feeding the reverse bulb. Make sure you use the right size tap. Once the tap is done,take the pigtailed piece, and attach it to #85 on the relay. You can fuse the feed wire that trips the relay. Use a 1 or a .5 amp fuse. Fusing the relay is not critical. It's just added protection for the factory wiring.


Hook the ground wire from each aux lamp, to the ground screw on the frame. You should have 3 grounds total.


Hook the 10 gauge POS wire to the battery, install the fuse(s), and you are in business.


NOW...... IF you want to be able to trip the lights from inside the cab, you will have to install 2 diodes, or else you reverse lights will come on when you hit the switch in the cab. All you need is a 2 diodes that are rated 14.5 volts DC, and have a 1 amp rating. Radioshack sells them cheap. Get the diodes that have 16 gauge wire so you can crimp them inline.


One diode goes on the POS wire, going from the reverse lamp, to the relay. Make sure the diode is "pointed" in the right direction. You want power to flow from the reverse bulb TO the relay, but not back.

Now take the second diode, making sure it too is pointed in the right direction. You want flow from the cab switch TO the relay, but not back. Attach one end of the diode to the 16 gauge wire, and the other end will go to #85 on the relay.

The relay will now have 2 wires attached to #85. One wire from the back up circuit, and one trigger wire from the cab. Each wire has it's diode at the end.

Take the 16 gauge wire, run it into the cab, hook it into a switch. All you need is a mini/micro on-off switch. You don't need a big toggle. You can use an illuminated LED switch so it's bright enough to catch your eyes and remind you the rears are on.

Now run the final wire from the switch, into the fusebox somewhere. Any circuit that is always live, or keyed. Whatever you want. Again, you can fuse the relay if you want. You're already taping into a fused circuit, and only adding about 1/4 (.25) amps to close the relay. A little more if your switch is illuminated. I wouldn't be concerned about it.


.
.
.
.
.
.
.
.
.
.
.
.
.
.

I hope that isin't too confusing. If you don't use diodes, then that 16 gauge wire has to be fused heavier to be able to power the revers bulbs. Now you'd want a bigger, redneck toggle switch.....lol. It's not a smart setup. Do things the right way....lol.


I think wiring should always be afforded the protection. Fuses are easy to check, and always give away where the problem is.

Anyway, just my opinion. All I can say is, use a big enough wire, crimp well, and shrink wrap all of it....lol.


Good luck.