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mtbtimr

Connecting light bar to high beams

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So currently, the light bar on my Forester is wired up with a Jaycar relay kit that connects to the battery with a simple switch in the cabin. I can turn the light bar on and off at any time (even when the car is off). 

 

To comply with the rules, I want to wire it up so that the switch is still there, but the light bar will only come on when the switch is on and the high beams are on. 

 

I've done a bit of investigation and probing with the multimeter and I know that the high beams are negatively switched. 

 

Can someone please tell me how to change the wiring on the switch so I get what I'm aiming for? 

 

Cheers

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the easiest way is take a feed off at the headlight bulb to a relay, then your feed to the isolation switch goes thru the normally open side of the relay before the switch.

I hope this makes sense

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2 hours ago, scratch said:

the easiest way is take a feed off at the headlight bulb to a relay, then your feed to the isolation switch goes thru the normally open side of the relay before the switch.

I hope this makes sense

Confused me a bit, so here's my take on the same scenario. I always find relays stupidly hard to explain

 

 

So the light bar side of the relay doesn't change (still hooked up to the batt).

The trigger of the relay changes. Instead of the switch opening/closing a 'constant' 12v source, the 12v source is actually fed off the high beam. So when high beams are on, you can flip the switch and the relay will turn on. If the high beams are off and the switch is on, there is no voltage/current coming through the trigger, therefore the relay doesn't switch.

 

And don't take the 12v off the lights side of the highbeams relay, take it from the switch side

 

 

 

 

something like this (i think)

CfUIeid.png

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Thanks@thewabbit1 that's what I was trying to say. I'll agree that relays are hard to understand.

Sent from my SM-G930F using Tapatalk

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@thewabbit1 If you could draw this up for me, I only use 1 relay when I wire up my driving lights on my subaru's. Hopefully I can explain it.

So the switched side of the relay remains the same, + batt to relay, relay to Lightbar/driving lights ( make sure it is fused ) 
the switching side goes like this, from a switched +feed ( i use the cigarette lighter) to your cabin light bar switch, from this to the relay, then from the - side of the relay to the switched negative on the Highbeams. 

I hope that makes sense ( i dont usually even run a cabin switch,I dont usually see any reason to have the Lightbar/Driving lights switched off :) which simplifies the wiring even more as i take the switched side for the relay straight from the headlight, one+ and the switched - ) 

 

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Hmmm... I think your way is more or less the same as above..... I'm no electronics guy so take what i'm saying with a pinch or two of salt.

 

The way your explaining (seems to me) is that your source to liven the switch for the bar is slightly different, by no means is it incorrect. Your solution (with a switch) would allow you to toggle the light bar when your lights are on (as you said). My implementation would only allow for the light bar to be toggled when highbeams are on (which is what OP asked).

 

All lights in a car will be on relays, t0o risky having a switch carry so much current, plus its easier to replace a broken relay than a whole stalk/switch. The only additional relay to include is the one for the bar, the other one is already in your car

 

 

I used this to make the diagram: https://www.circuitlab.com/editor/#

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No switch has any more current than what is required to run a relay. 

 

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The high current only passess through the switched side of the relay

Edit: whereas if you were just using a switch you'd have that high current in the switch and burn it out.

 

 

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Yup 
trying to work that website but meh not working 
 

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On 7/7/2018 at 1:17 PM, mtbtimr said:

To comply with the rules, I want to wire it up so that the switch is still there, but the light bar will only come on when the switch is on and the high beams are on. 


Light bars are a notoriously grey area. Perspectives go from all ranges for police and WOF inspectors... I failed my WOF with the light bar switched via high beam. To pass I just unplugged it. It is on a on/off/on switc either way. On whenever I want, off completely, and on via high beam.

Regardless of what your WOF inspector rules, be aware that you might get a fussy cop who doesn't like seeing you using it either... use at your own risk really

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8 minutes ago, Nachoooo said:


Light bars are a notoriously grey area. Perspectives go from all ranges for police and WOF inspectors... I failed my WOF with the light bar switched via high beam. To pass I just unplugged it. It is on a on/off/on switc either way. On whenever I want, off completely, and on via high beam.

Regardless of what your WOF inspector rules, be aware that you might get a fussy cop who doesn't like seeing you using it either... use at your own risk really

 
 

 

Yep, I'm going to print off a copy of the wording from the NZTA website to keep in the glove box. 

 

M8LebUl.png

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Things they can pull you up on

1/ "driving" lights are supposed to be in pairs( a light bar is one single light, I have seen people put a piece of tape vertically down the centre) 

2/ Placement, the light bar is supposed to be between the headlights even with them. 

My hilux setup kBuVgP4h7nbmSYt9_enl5aiNKG-l1oCOFajIqhi_fP5PhZHVD8yEulI6td-l4Eo7BgHjZaQYrlSbfr6qRtnZ9dBLAZnGk4KdztOkRSEScEzi4iCKS_WRLCEXWuAntblmVaEJLo_DYWxNfdZEOMn5k6rf9hYiPciFoYYIMykGSHMqt5sCARmZ9Nk1lEkke9PfNYptyN0U12d8BstLbxFiRKNSfxBa45xQt2vBkdBOFDSZCxo65Ror6uio7u1M3BurD08kdlJlL0FTkqF5Rsgi64_3i_u5nzb3TVbVj4Zaay9N7TT9WSuEmC-YTWPDcHMfgJEyhppNRmBydszukBFEu-kAGYqWOe98iHIqwN9I6UXhM5Qo3aXkZE_MTjCnbMx48kbJeRGRigutkW2PIJ23pvD4XkLD68Jn0ln7_P6LcUEcI_-3GRmmn7tKtCeohJW-cc2CPr6wJ6zxOiOtgTuPg2BSFRa4S8_3MtCZcjcQrc_j4SUyH0HiYhmAqyvguZoRrsDOlU4qDe_xzCbTE5ewczaXKffx5IRxFmGaAN5lpTd4qn-mGIEenX87wmRoQ8UBmZEwU9O7J--pCody_1SvdzzgbbbCIvygcf2Oeftp=w1314-h986-no

 
essVo1IWiqTWUZkBciDeTi9drawpJOwuI-9PvImJmVwV2Gl7CfDdNyJFwcNyuA-wVs-XvmZEFDjBebOMpnTHd067ahG0HsL4xmIigUSGebe7NOryzNynkbBQIKCKTUk1TkHjzdR2BtNQKnaEv5Z-_3xb4ruwaP8yxMau9Kz2kPFsQemxhDxDTm3JOr9b3sSguATOl7ZivXH2ZaxIcYND0LI2UPVXIx39ykOFprJJiiblo04bs3pSyyMHizQRIeq7JPUqd0mlBuB1NnTuvQ67o_6Xiuuib12F3byLmd32TYq7bVOO2ZWw1BrS3pCpEjekoiQg42oQSrxmACMs0GWS_Ne8GzdDv1e5PAb0PG6dQomHnEbQSQryuCuLObC8uEv2E2VrG3QYQ2BgM5eOlBc8Xpk6tQe_dDw83ri5azxnnBTwyAZ74qEWca4U-urjUarPOQaF9SLAc-Tp_XkqSc0nPmBtoFvniouI9TIWtl7Si3x1mZL3DJsqyjNS60mhc9ifkoIzAshSlNHjy0NIHn9mFcJB6p5wb-wJLTOR2EbsfroQAx3jpDiZ1X3GC9pBA0CJPUPcC8Ual-BGJOzdlPSg05tapyFvDWZ6UGj9T5rZ=w1314-h986-no

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4 hours ago, mtbtimr said:

Yep, I'm going to print off a copy of the wording from the NZTA website to keep in the glove box. 


Yeah what DRFVDR explained is true. Unfortunately it's all up to interpretation, no specific legislation for LED bars..
I had a chat with one of the NZTA WOF auditors about them, and he was not a fan at all. Rather annoying considering they're (LED bars) are a modern part, readily available and are being fitted more and more. It didn't sound like there were any long term plans to introduce some new specific ruling around them either... Frustrating really

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