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wlee69



Member Since: 25 Mar 2017
Location: Groton, MA
Posts: 5

United States 2014 Range Rover 5.0 SC V8 Mariana Black
Help on wire that triggers high beams

I have installed a led light bar behind the grille of my 2015 RR SC. Its pretty stealth looking and brightens up the road at night when no other car is around!! (Trying not to blind on-comers). I'd like to connect up the wiring harness to come on only when the high beams are on.

I have the Topix wiring layout and do not see any specific wiring for the highbeams. I see a wire for the bi-xenons and then another called the "main beam flap"..others are the DRL, sidemarkers etc. When I test for power @ the wire loom at the headlights, both the bi-xenon and main beam have power regardless of low/high beam.

Am I looking at the right place that will trigger that high beam?

Thx,Will

Post #472959 17th Mar 2018 7:08pm
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nicedayforit



Member Since: 11 Jun 2011
Location: Beside the Solway
Posts: 3201

England 2004 Range Rover Vogue Td6 Giverny Green

I think what you need to do is check the voltage on the " main beam flap" wire with the headlights on main beam and then on dip beam. With a bit of luck the voltage will change from +12V to 0V as you switch from one setting to the other.
Depending which way round the voltage changes you should be able to switch either a normally open or normally closed relay to operate your light bar so that it comes on on main beam headlight.
Any chance of posting a picture of your light bar setup?

And welcome to the site. Thumbs Up I haven't lost my marbles, they're in a bag somewhere

Post #472970 17th Mar 2018 9:13pm
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Cam-Tech-Craig



Member Since: 04 Aug 2011
Location: Gloucestershire
Posts: 12066

England 2007 Range Rover Autobiography TDV8 Java Black

I have fitted a light bar too and use the flapper motor power to run a 12v spot lamp relay, i found the light bar would start to flash/strobe and eventually knock/trip the LCM out without the relay... A cycle of the ignition would auto correct the LCM but still, be warned the LCM doesn’t like powering too much extra stuff Thumbs Up Site Supporter

Post #472981 17th Mar 2018 11:27pm
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wlee69



Member Since: 25 Mar 2017
Location: Groton, MA
Posts: 5

United States 2014 Range Rover 5.0 SC V8 Mariana Black


Thanks for the help in pointing me to that particular wire. Now that I'm honed in on it, its actually gives our 8V at rest and with the low beams on....but then goes up to 12V with the high beams on. I'll have to see if I can use it as a trigger with it giving out 8V at rest, hopefully the relay won't go till it gets a full 12v. Will let you know.

I took some pics of the setup, didn't take the grille off again, but when you take the grille off I have the bar mounted right at to far two bolts that hold the bumper over in place. The 30" curved light from BlackOakLED with brackets fits right in that spot. Had to do a little dremeling on the inside edge of the grille as the grille curves more at the ends than does the light....

Getting power right from the battery jumper stems. And I've wired in a remote switch with an FOB. Ideally would like it just to turn on with the highs on, but with the FOB I have the option to turn it off also.

Attached are some pics






Post #472985 17th Mar 2018 11:47pm
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wlee69



Member Since: 25 Mar 2017
Location: Groton, MA
Posts: 5

United States 2014 Range Rover 5.0 SC V8 Mariana Black

How soon would the light bar start to flicker? was it after it was on for some amount of time? or was it from the relay going on and off (like if you have your lights on auto high)??

Just wired everything up and then so your post on the LCM.....just trying to figure out what they symptoms look like and perhaps its not a good idea to run off the high beams!!

Thx,Will

Post #472989 18th Mar 2018 1:52am
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nicedayforit



Member Since: 11 Jun 2011
Location: Beside the Solway
Posts: 3201

England 2004 Range Rover Vogue Td6 Giverny Green

I have to agree with Craig re using a relay. I personally wouldn't connect any additional bits to these cars without using a relay. I use a relay switched from the flap wire to switch a light bar without issue to date. I haven't lost my marbles, they're in a bag somewhere

Post #472994 18th Mar 2018 8:39am
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wlee69



Member Since: 25 Mar 2017
Location: Groton, MA
Posts: 5

United States 2014 Range Rover 5.0 SC V8 Mariana Black

Mine is connected the same way. Connecting to the main flap is just to trigger the relay....the main battery is powering the actual light bar! Thx again for the help!

Post #473010 18th Mar 2018 11:45am
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nicedayforit



Member Since: 11 Jun 2011
Location: Beside the Solway
Posts: 3201

England 2004 Range Rover Vogue Td6 Giverny Green

Thumbs Up I haven't lost my marbles, they're in a bag somewhere

Post #473013 18th Mar 2018 11:51am
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Cam-Tech-Craig



Member Since: 04 Aug 2011
Location: Gloucestershire
Posts: 12066

England 2007 Range Rover Autobiography TDV8 Java Black

The light bar would start to flicker around 30 seconds after start up WITHOUT using a relay, it would then knock the LCM out 10-20 seconds later... Thumbs Up Site Supporter

Post #473032 18th Mar 2018 2:52pm
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Cam-Tech-Craig



Member Since: 04 Aug 2011
Location: Gloucestershire
Posts: 12066

England 2007 Range Rover Autobiography TDV8 Java Black

A quick thought, how do you wash your light bar if its behind the grille? Site Supporter

Post #473033 18th Mar 2018 2:52pm
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wlee69



Member Since: 25 Mar 2017
Location: Groton, MA
Posts: 5

United States 2014 Range Rover 5.0 SC V8 Mariana Black

I swapped out the grille and put in a different one to let more light through....as far as keeping the bar clean, I guess you just spray thru the grille? Too much of a pain to get the grille out each time....

So far so good with the wiring to a relay, have the lights set for auto and the high beams are coming on and off as expected!!

Took a pic of the bar also while the grille was off....






Post #474614 3rd Apr 2018 1:01am
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