Hardwiring extra light

Im about to use a wire tap to add some extra lights onto my parking light hot wire under the hood. I have 2 lights im adding. I was going to tap the driver side and passenger side hot wires, will I see any problems doing this?

 

What kind of lights are you adding? Typically, it's a much better practice to run the lights using their own power source and fuse and only using the parking lights as a 'trigger' if that's how you want them to operate. If you're taking just additional marker lights though, I don't see a problem with simply tapping in.

 

I make it a habit to run everything from its own power source, with a switch, fuse, and relay...... Never had a problem yet, but tapping into power is ok, just make sure to secure all connections before shutting the hood and forgetting about it.

 

I did a custom backup/aux light install and used an "add a fuse lead" to obtain power at the fuse panel for the pair of low wattage tractor lights.....it was really handy and close to my new switch

Want to try a relay some day to learn how when I install more powerful off road lights

 

When you say trigger do you mean using the parking lights as the switch for the new lights? Because if I could set then up with their own power source and just my parking lights to turn them on and off I would. I want the extra ones to turn on and off with the parking lights

 

That's exactly what I meant. If you're just talking a couple LEDs or an extra marker light, there's no harm in simply tapping into the parking light. If you're talking something more substantial, I would say give them their own fused power source and use an automotive relay to make them come on whenever the parking lights are on and turn off when the parking lights are off.

Here's your basic automotive relay (make sure you get a 4-pole, some have 5 and are for a different use).
85 would be the tapped power from your parking light
86 is your ground
87 is the power output to your added lights
30 is the fused power input (power source for your added lights)
With this wiring set-up, everytime you turn your parking lights on, the added lights will come on with them. Depending on the lights you're using, you might want to consider a hidden switch somewhere in case you want to turn on the parking lights and NOT have them come on. Even if you leave the switch on 100% of the time, it's easy to wire one in, it could even be an all-weather switch mounted in the engine bay if you didn't want it in the dash.

 

thats a great explaination! I'll make sure and do it like that. Will the prongs be numbered on the relay so I will know which ones are which?

 

Yep, there will be numbers on the relay so you know which prong is which.

 

The lights are going to be 12 volt, 55 watt project fog lights. I was thinking of getting a 55 watt H3 HID conversion kit for them later on. Would that work if I was use the set up you just described?

 

Yes, that will work and you'll definitely want the added lights to have their own power source. You don't want 55W pulling off the parking lights circuit. I would very strongly recommend putting a switch in there also. There will be times that you might want to turn them off manually either in heavy fog or snow. Adding a switch is very simple, put it between the in-line fuse and the relay so you can cut power whenever you want. That way the lights will come on when the parking lights are on AND the switch is on (leave the switch on 100% of the time and you'll never know it's there).

 

great diagram..thanks Pugga

 

Auto wiring, normally is setup to use only the pwer it is designed for. So with that said tapping into the power of a circuit is frowned upon. Inthat the fuse panel is not rated for the extra load. You can tap into the switch for say parking lights to make them come on and off but do not run 55w fog lights on that circuit. Also do not nix the relay ever. You wanna keep alll that power under the hood and not in the cab. Hence the big fuse panel in engine compartment and mini by the drivers left knee. That relay will save your life. As a control person, relays are great.

Just remember that the vehicle and its entities are rated for what they have. If you wanna add electrical extras do so with added relays and switches and dont try to add to a sytem Toyota engineered and rated for what it has, cause they didnt do it with the forethought of owners adding enough lights for Fenway Park to be lit up.

Just one mans opinion. And a ton of mechanics at work too!

 

Haha, you have some great points. Thank you for your help!

 

I've noticed that switch have three prongs in the underside of them. How would you put that in between the fuse and relay? Wiring is the worst thing for me, anything else I can deal with. Haha

 

Not sure...I am challenged as well .....must be like the one I used

-one goes to power
-one goes to ground
-one goes to light

Maybe you need a simple 2 prong switch for this

 

Easiest explanation
1- ground
2- power to
3 power from

you basically tell the relay to energize or not. Without the relay all that power sits on one side of the switch. So with a relay the power is at the relay and not in the cab.

 

Thanks for helping us understand this....so the relay is a much safer way to wire accessories.

You have me thinking of redoing my wiring now that I realize (very logical) that the power I am drawing from the cab panel is always sitting on one side of my cheap switch.

 

... ^^^ ... Bookmarked ... great wiring diagram & explanation ...
.

 

just googled this...good stuff here!.....plus tips on wire, wire guage etc
http://www.therangerstation.com/tech_library/relays.html

 

What gauge wire would y'all use? I was thinking 12 gauge would work, maybe 16