Ho do I wire lights 4 running brds?

[Heartbeat Hauler]

When I'm running at night it gets kinda tough to see the rear wheels in the mirror. So I was thinkin' I could install a set of license plate light units at the rear of the running board(I have a set of the Glasstep by Owens). They are directional and I could aim them at the wheel without blinding someone next to me. But I don't know how to wire them up to come on when the other lights come on (auto)without cutting into the system. I heard that was a bad thing. Any ideas?
JP

[Alli-max]

I dont know how that would be bad to tie into a hot wire unless you didnt waterproof it.

Simple tap into a hot wire when the lights are on, but personally I would break the current with a switch in the compartment.

[ratlover]

I would (and will when i wire in my aux lights) use relays. Run a wire from the relay to what ever you want the light to come on with. You could use your reverse lights or even your defroster and not worry about drawing too much juice through the fact wires. Adding a switch on the relay wire might be a good idea depending on your application. A relay(I dont mean to insult your inteligence if you know) is basicly a switch that gets turned on or off by electricity. You can have relays that normaly let juice through them but close if you apply juice to the switch wire or ones that are normaly closed unless you apply juice to the switch wire. The switch wire(from what ever you want the relay to work off of) dosnt draw much juice so you dont have to worry about overloading a circut it is drawing off of or voltage drop. Make sure they are high enough rating for the amount of juice you will pull through them and waterproof if they are going to be mounted outside.

I will cut away the insulation and insert a probe into the middle of the strands of factory wire to be "switched" off of. And put an end of stripped back wire through the hole I made and wrap the end of the stripped wire around the whole mess a few times. Solder that and wrap it good. IMO regular old electric tape isnt a good idea by itself for an outside application. Selfvulcanazing tape works ok with electrical tape over that or there are some better tapes and shrink sleeves and the like. Or you could run this wire right to what ever you want to power but most things I prefer to use this wire as the "switching" wire for the relay. The "treading the needle" approach means no cutting of the factory stuff and a good strong conection. I dont like scotchlocks personally but they are another alternative.

[Heartbeat Hauler]

Allimax,
I thought about a switch, but it seemed it would be cool for the new lights to come on & go off with the factory lights. Is there a reason why you suggest a switch, maybe a safety thing?
ratlover,
So then what you are saying is:
Find the hot wire,i.e. parking lights, then solder a wire to it. Then run the new wire to a relay, and from the relay to the two lights I want to add. Then when the lights come on (parkng lights)this will energize the relay and consequently turn on my new lights. Is this correct?
JP

[ratlover]

Yup, the relay actually has 4 wires. I wasnt very good with my first description.

One "switch" wire either normaly hot or normaly not, depends on what relay and what you want to do. You would have a wire that gets energized when you turn on your parking lights say. One ground wire. One constant hot wire in(from the batt say or any other sutible sorce) and one wire out to the device you are wishing to power. This wire will get juice when the switch wire goes hot in this case but you can get relays that effectivley turn this wire off when it sees juice from the "switching" wire.

When you said you couldnt see your back tires I figured that you wanted to see your back tires when backing and thus wired off of the reverse lights would be a good choice. I figured on using relays because i though you were going to mount some higher draining lights like a offroad light or something(I've seen it done pretty stealth like) But if you are just running some fairly low draw lights then you could skip the relay and wire it direct. I think allimax was meaning have them wired from what ever you want them to turn on with but with a switch in there so you could turn them off if you wanted. With the switch in the on position they still wouldnt come on untill you turned on whatever yu wanted them to come on with. If you were going to put a switch on them then I would highly recomend a relay then and you place your switch on the "switching" wire for the relay.

That make sense?

[Heartbeat Hauler]

I dig.

Basically I'm using some aftermarket license plate lights to see the rear wheels when driving. I can't see the tires at night when making a turn and those curbs keep jumping out at me.

Appreciate the suggestions and the wiring 101 class. I love this forum :D
JP

[ratlover]

Maybe some of those light up caps like the ricers use on thier tire valve stems tongue.gif smile.gif

The truck was ment to run with lotsa trailer lights and such, if you dont ever see the need for turning them off then you could probably skip the relay since those lil buggers couldnt suck that much juice I wouldnt think.

[HowieE]

As mentioned above you can relay off the parking light circuit but I would consider putting a momentary switch (normally open)inline with the feed from the parking lights. Then when ever you touch this switch, as long as the parking lights are on, the lights will come on. I mention this only because some States may have regulations about "white lights" shining rearward while going forward.

[Heartbeat Hauler]

Howie,
Thanks for the heads up.
JP