12 Volt Gurus

[Coreshot]

I'm looking at installing some rock lights on my Wildcat, but want the stock taillights to work with them while keeping the headlights turned off. So, I want the taillights to work on 2 separate circuits. Is there a way to wire the taillights into this circuit without backfeeding the running lights circuit? I'm picturing a sort of isolator wired into both circuits that wont allow back current on the other. If this is possible, what would happen if both circuits were under power at the same time? Thanks

 

[MikeGyver]

Could you wire a relay between the headlights and ground in the normally closed configuration? When you energize the relay the headlights go off.
The other way it to use an appropriate diode as a "one way valve" so current doesn't 'backfeed' into everything else. The type of diode you want is a Schottky diode (low forward voltage drop and say double the current rating of whats actually going to be going through it.) radioshack, ebay, etc.

 

[Kevin B.]

(nevermind)

 

[jackjoh]

Or just two separate circuits with two switches.

 

[cjncustoms]

Do your park lights/tail lights come on separately from your headlights? If so, you could tie into the taillight circuit and run it to a switch and then to your rock lights. That way you could use your taillights as normal function and then your rock lights would only be able to turn on if your taillights are on. Make sense? No diodes, no relays(as long as the amp draw is acceptable).

 

[UFAB]

Use a 5 lead relay, check link out

http://www.mp3car.com/the-faq-emporium/117895-faq-relays-how-they-work-and-how-to-wire-it-up.html

 

[TurboMinivan]

you could tie into the taillight circuit and run it to a switch and then to your rock lights. That way you could use your taillights as normal function and then your rock lights would only be able to turn on if your taillights are on.

This is what I would suggest, though I would recommend using a relay triggered by the tail light circuit rather than just tying into the tail light circuit itself. Relays are cheap insurance when it comes to adding electrical loads.

 

[Alcancia]

Do your park lights/tail lights come on separately from your headlights? If so, you could tie into the taillight circuit and run it to a switch and then to your rock lights. That way you could use your taillights as normal function and then your rock lights would only be able to turn on if your taillights are on. Make sense? No diodes, no relays(as long as the amp draw is acceptable).

I don't think the taillight comes on independently of the headlight. I could be remembering wrong, but I'm pretty sure it's just an on/off switch for all lights. Or more likely an Off/Lo/Hi switch where the taillight is on for the Lo and Hi beam either way.

You can still make it happen with a 5 pin relay though. This is a crude, crude schematic, but hopefully enough to at least get the idea across:




With this setup on a standard relay, you would wire the terminals like this:

87 - Fused +12V
87A - +12V currently going to taillight when lights are on
30 - To taillight
85 - Ground
86 - +12V from rock lights

That's on top of the fuse, relay, and switch you should put in for the rock lights themselves.

Hope this helps!

EDIT: Reading your original post and seeing the concern about "what if both circuits are turned on at once?" With the schematic I provided, you would be able to turn on the rocklights and the headlights at the same time with no problem. The relay only contacts one circuit at a time, so it doesn't matter if they are both on.

 

[Coreshot]

Thanks guys. Yeah, the taillights are wired like any car, come on with the headlights.