Game Fishing Forum banner
1 - 7 of 7 Posts

·
Registered
Joined
·
5,603 Posts
Discussion Starter · #1 ·
I've installed a pair of flood lights under the back-bumper of my truck. Currently I have one wired into the back-up light circuit, and the other is wired with a switch to a constant 12v source. I would like to wire them-up, so they both come-on with the b/u lights AND/OR can be switched-on from the constant 12v source. I guess that I'd need some-sort of relay for dual power sources to a single accessory, but I wouldn't begin to know where to find one. Anyone have a suggestion?
 

·
Registered
Joined
·
3,303 Posts
I'm guessing there around 55w each? Honestly, i'd just try to use wire splice clamps and crimp them to the +/- coming off both sides of your reverse light bulb plugs. That kinda depends on how much draw they have though. You may just be able to put in a higher amp fuse. If you want it on a switch, just get some 14-16 gauge wire (black and red) and make a harness like this.



Radio shack should have everything you need.
 

·
Registered
Joined
·
2,213 Posts
Any auto parts store will have a relay. Just tell them you want a standard run of the mill relay for auxillary lights. I bought the Chev aux light switch (for snow plows) looked great but died within a month. (It goes next to your airbag switch.) After that I hooked it to the cargo light switch. I like it better that way then always having it come on with the back up lights.
 

·
Super Moderator
Joined
·
1,972 Posts
I'd say you're looking for a two pole relay with a two position output. This relay has two terminal inputs and two out. The relay will have a default state, either NO (normally open) or NC (normally closed). As a default one input side and one output side with either be NO or NC.

With a two pole two position relay find the default closed circuit (NC) side of the relay and connect this to constant + battery power. Then continue the positive lead from the NC terminal output and connect it to a toggle switch of your choice, the continue the + lead to the light. And connect the + accessory power from your back up light circuit to the "normally open" input side (you may want to "Y" this out to keep your back up lights off the relay). Then tie + out from the NO output of the relay on the other side of the toggle switch (or lamp side of the switch. As for the other light, simply paralle the cable over to the second light. Used deoxidizer on the external connection at the lamps.

Now when your vehicle is off, you should have constant power and on/off control with the toggle switch. When you turn the vehicle on, the relay will charge and throw to the other pole for your back up lights purpose.

Basically, running two + power into relay (one off battery to normally closed side of relay, one off tail light circut to the relay to the normally open side closing the circut when vehicle charges the relay). Keep the negitive "-" side connected throughout the circuit since you only need to alter the + power source. (2) + in and (2) + out to lamp with one switch thru put on one relay output.

You'll need a 12VDC relay rated for the load (amps) you need. Should be able to find it at an auto parts store, or if not, try an electrical supply warehouse


I think this is right. I hope this helps
 

·
Registered
Joined
·
5,603 Posts
Discussion Starter · #6 ·
Thanks BigWorm, that's exactly what I want to do! I'll go a-searchin'.
 

·
Super Moderator
Joined
·
1,972 Posts
NP. You may want to draw it out on paper (left to right, power source to lamp) this way you don't get mixed up during the install. Just remember the + pathway as "in" and "out" with two input circuits and two outputs with one bypassing the switch.

Good Luck Tup:
 
1 - 7 of 7 Posts
Top