Help wiring light bar...

[jasondavidmann]

Hello I'm hoping somebody can help me figure out my wiring problem for my light bar.

I'm building a light bar for my (embarrassed to say) minivan for when we have to drive through the night down old highways and gravel roads.

I have put two switches on my dash to control the two lights on the roof. I want to have the option to have the aux lights to come on and off with the the hi-beams. The other option that I want is to turn the lights on or off with a separate switch.

Please see the attached diagram to see my current wiring. Note that I'm confident that my wiring gauges are adequate. I am also not using a relay for lighting option number 2 because I am using heavy duty toggle switches that can handle the amperage.

HERE IS THE PROBLEM: When I put the option one (on and off with hi-beams) switch in the on position and turn the hi-beams on the wire from the circuit breaker back to the option two switch gets really hot (I am assuming it is grounding some how). Each option works fine if I only hook one up to the circuit breaker at a time.

Do I need to put a diode or something to prevent the backwards flow of current from the circuit breaker?

Thanks for your help.

Jason

 

[Bullseye240]

You can do the same thing with a single center off switch. You wire the center spade to the relay control spades. One of the outer spades goes to 12v positive to simply turn on the light. The other one goes to the headlight high beam wire. This way the relay still controls the current of the lights and the switch simply determines where the signal comes from. No diode needed and you only have to run one set of wires to the lights. With your current setup you are most likely backfeeding the other circut. I use the same setup I just described to control electric fans. Instead of the headlight high beam circut it's a tempeture switch controling it. Sorry for the lack of fancy diagram. Just kidding.

 

[StumpXJ]

Why are you grounding the switches? Are they lighted?

~James

 

[jasondavidmann]

Thanks for your responses.

The switches are lighted when in the on position.

I would like to have it setup with the two separate switches because they are already installed. I did think about switching to a 3 way switch after I realized that I had a problem but the switches already match my others. I wonder if I would have a problem if I disconnected the ground on the option 2 (manual control) switch. I still would prefer to have the switch light up when on.

 

[alexrex20]

you can keep your switches, but you still need to run them on a relay. your current is bottlenecking in your circuit because when you flip Switch #1 to ON, you're routing the hi-beam and aux. lamps through that switch.

Bullseye did indeed hit the bullseye. you need to run relays. for Switch #1 your power will come from the Hi-Beam hot side; on Switch #2 your power will come from any circuit that's live with the key in the ON position. (i'd recommend NOT wiring directly to the battery because if you or someone leaves the light switch on, it will drain your battery.)

 

[jasondavidmann]

Ok thanks guys, I will add a relay between switch 2 and the circuit breaker, that should fix the problem. Thanks again for your help

Jason

 

[blueeyeddevil]

You really don't need all of those relays and such. Just take the power through your O.E. light switch, then you can use the factory relay.

Power from O.E. light switch (low beam side) to your switch. Then to the lights.
When the high beams kick on the power should be interrupted to your AUX lights.
If you run a "on-off-on" switch, you can then run the O.E. config.. Plus, run power from an Ign. on source to the other "on" side of the switch and have manual control as well.

Depending on how many amps your Aux. lights draw.
I would recommend these-
http://www.visionxoffroad.com/led/s1100/

900 lumen / .75 amp draw
Build them as you go.

I can get them for $125.00 ea. if you are interested.

 

[irsa76]

I beg to differ. You should ALWAYS use seperate fuses and relalys for additional lights. That way if you damage one of them, or have a short for some reason, you don't loose all your lights.
Personally I would run a fused relay to the lights with one switch drawing from the highbeam circuit as per normal driving light installation, with the second switch drawing from an igntion switched source, I've used the stereo main power feed before. On the output side of the switches use a diode on both switches to avoid backfeeding the other circuit, then connect both switch output wires, after the diodes, to the switch pin of the relay using a piggyback connector.
Actually, to be completely honest I'd just use the one switch wired to the highbeam circuit and leave the other as a spare, or mount some more lights wired as above for a single switch.

What sort of minivan is it btw? I've got an '03 Chrylser that I'm planning on running some aux lights on in the near future, tomorrow if I had the money!

 

[jasondavidmann]

Hi,

Yeah I agree anything auxiliary should be wired separately, you do not want to take out anything that you really need.

The light bar is on a 2002 Toyota Sienna. I just drove across northern Ontario through the night (read in the dark) the lights worked really good, they really helped me see all the moose.

here is a link to my light bar photo album