12v lightbar on high beam switch installation

[BoxMN]

This is actually for my atv, but thought maybe more pros would see it here.

I have a 12" LED light bar I want to install on my Foreman. I also got a wiring harness with a relay and waterproof, lighted, switch. I have the mounting position (basically where a winch would go).

Can I just tap the switch lead into the stock high beam wire to have the light bar only come on when I hit the high beams? Of course, the relay would be wired to the battery  as it should. So in this image it would be the 12v in from fusebox...?...

Or should I just wire it direct to battery and use the switch "manually"? I also have two sets of leads on that harness, so I was figuring just wrapping up the other and leaving it zip tied in hidden area. Is that acceptable?

Thanks, I am no electrician but haven't fried myself yet, and do't want to

[Jeremy airjer W]

If you only want it on when the high beams are on why have the switch?

otherwise your plan looks legit.

[delcecchi]

You won't fry yourself with 12 volts unless you try really really hard.  You might fry some vital, inconvenient to fix, wires however.  Diagram looks good.   Seems to me that sometimes they used to put the switch in the ground leg.  I'm not sure why. 

[Jeremy airjer W]

If you put the switch on the ground side than the load of the circuit has already been used by the device. this would be done if the circuit had a higher load demand to keep the switch from burning up due to the amount of current that would have to pass through. So lets say you just ran power to the light straight from the battery. If you put the switch before the light than all the load needed to power the light has to pass through the switch first, which can cause the switch to burn up. If you put the switch on the ground side the load has already been used by the device and the switch is just completing the circuit.

in your case the switch is on the low side of the circuit (a relay controls large current with small current). so it does not matter where the switch is.

hope that made sense......

[delcecchi]

The explanation was a little confusing.  I thought it had something to do with convenience of wiring, like you could run 1 hot wire and use chassis as ground and save a few cents.  But I could be totally mixed up as it was a long time ago.   I remember some car wiring was sort of strange. 

[rundrave]

I know on the polaris models there is an extra set of "Accessory wires" under the hood that you can tie into. Perhaps your Honda has the same? In my case my 500 had 2 sets and are activated with the OEM light switch. I used these for a similar situation to yours. One is for a winch and the other is for some extra lights I mounted similar to what you are installing.

[BoxMN]

Thanks guys. Yeah, now I am thinking not putting them on high beams and just using the switch manually, or maybe putting them on the normal light but still keeping the switch. I am just thinking there may be times when I don't want the real brights - ie leave the switch always on, except maybe if i DON'T want them for some reason.

I will look for extra wiring under the hood as well.

Thanks!

Edited January 13, 2016 by BoxMN

[Whoaru99]

On 1/13/2016 at 8:17 PM, delcecchi said:

The explanation was a little confusing.  I thought it had something to do with convenience of wiring, like you could run 1 hot wire and use chassis as ground and save a few cents.  But I could be totally mixed up as it was a long time ago.   I remember some car wiring was sort of strange. 

 

Current is common in a circuit. What goes in must come out. Current through the switch is the same regardless if on supply side or return side.

I think low side switching is often used in electronics because I seem to recall N-channel devices generally have lower resistance and the circuits to turn them on/off are less complex than for P-channel device on the high side.

Edited January 14, 2016 by Whoaru99

[jmd1]

So we used the same type of set up on most of the fire service systems.  However when small lights were part of the switch we found that controlling the hot side would cause failure of the light in the switch.  So through engineering, we moved the switch circuit to the ground side to control the spike on the switch.  Today, this is how most of these units are wired.  I also when ever wiring anything will break the ground over the hot side just to keep that spike under control.  if one wanted you could fuse the ground side incase of a failure but rarely needs it.  

So in your diagram if you jump from 30 to 85 or 86 can work on both sides, run ground to one not used 85/86 and install the switch then 87 back to the light.    this will work seamless and makes it a bit easier to find a problem if you know the ground is controlling the light. Plus side is you eliminated 2 hot wires that could go to ground and melt the whole mess down.   good luck

Edited January 16, 2016 by jmd1

[Whoaru99]

That sort of relay is typically available in three styles.

Unsuppressed, resistor suppression, and diode suppression. Usually the resistor supression is sufficient to prevent flyback spikes from damaging the control circuit. But, diode supression does it for sure.

[BoxMN]

Well I added in the harness (relay with two sets of leads) and was able to mount my 12" light bar and connect it very easily, and also found the leads from my grip warmers and wired them to the other lead. Both the light and the warmers are working great! With both on the same switch, the lights need to be on if the warmers are on, but the warmers can be off with the normal switch as well. The warmers were there when I bought it, but the guy had them disconnected I think due to him leaving the warmer on too many times and wearing battery down, ha!

The LED light is pretty okay, more of a flood than a spot, but it does brighten things up with more of a white light than the yellowish headlights.

I was going to put a small 4" LED on the back of my winter rack for lighting up to take down portables etc. but my space in the battery compartment is getting tight, haha! Hardest thing was routing the wires, but I wanted it doe nicely so took off the plastic and routed it factory looking, inside plastic sheath/cover. Switch is nice and red lit so no mistaking leaving it on. Using a commercial harness (about $15) made it really easy and professional looking. time will tell how quality it is.