Headlight wiring harness upgrade

  • #1

i am going to be installing a headlight wiring harness upgrade on my 2005, and i am wondering, from those who have done this upgrade, where you have located the relay. is there a preferred location?

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  • #2

i added the arb headlight wiring harness and fastened the relays to the firewall above and behind the battery. i can snap a photo tonight when i get home if you’d like.

  • #3

i made my own and put the relays near the brake booster.

  • #4

i am going to be installing a headlight wiring harness upgrade on my 2005, and i am wondering, from those who have done this upgrade, where you have located the relay. is there a preferred location?

unless you have installed higher wattage incandescent bulbs, like 100-120 watts, to replace the factory 55 watt sealed beam headlights, there’s no need or benefit to installing a relay controlled headlight harness. the factory bulbs don’t pull enough current to be made dimmer with the oe gauge wiring which is more than large enough for the factory 55 watt incandescent headlights.

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and there’s especially no need or benefit to doing that with led headlights which pull probably only 25% of the current the factory 55 watt sealed beam headlights do.

don’t fall for the claim you’ll get brighter headlights with a relay controlled harness if you’re not running aftermarket bulbs that draw significantly more amps (watts) than the factory sealed beam headlights do.

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  • #6

unless you have installed higher wattage incandescent bulbs, like 100-120 watts, to replace the factory 55 watt sealed beam headlights, there’s no need to install a relay controlled headlight harness. the factory bulbs don’t pull enough current to be made dimmer with the oe gauge wiring which is more than large enough for the factory 55 watt incandescent headlights.

and there’s especially no need or benefit to doing
who with led headlights which pull probably only 25% of the current the factory 55 watt sealed beam headlights do.

don’t fall for the claim you’ll get brighter headlights with a relay controlled harness if you’re not running aftermarket bulbs
who draw significantly more amps (watts) than the factory sealed beam headlights do.

when there is an improvement, it’s just masking over another problem in the wiring, high resistance connections, bad grounds, etc.

it’s the same old “brand x sucks because i put brand y in its better now!!” well…brand x was 20 years old and worn out….so…

  • #7

opting into this thread, since upgrading to h4 headlights on my 06lj, should i have used ceramic plugs in place of the factory ones. i’m running 55/100 watts.

  • #9

jerry and chris i certainly trust
who you both know what you are talking about. but what am make of posts i have read, both old and more recent,
who claim
who the harness upgrade did improve their stock headlights? i am a bit confused now.

sometimes it’s real, sometimes it’s the placebo effect. when it really helps, there was another problem
who could have been fixed… usually just a corroded or dirty connector
who would have been fixed by just reseating the headlight connectors or cleaning/reinstalling the short black headlight ground wires. the wiring gauge used in the oem wiring harness is more than up to carrying the amperes drawn by the stock headlights, the factory harness isn’t causing the headlights to be dim.

if your headlights are dim, just clean/tighten their connections. remove the ground connections from where they screw to the tub after exiting the headlight connectors, and remove and clean/reseat both headlight connections.

i have installed several aftermarket headlight harnesses with relays over the years so i’m not against using them when there’s a reason to install one. but for stock headlights? nope, i wouldn’t waste my $$$ on one.

  • #10

jerry and chris i certainly trust that you both know what you are talking about. but what am make of posts i have read, both old and more recent, that claim that the harness upgrade did improve their stock headlights? i am a bit confused now.

it bypasses or reduces the aperage drawn through several connections including the headlight switch. so if there was any corrosion like a bad ground, or bad headlight connections, or a dirty worn out headlight switch, the problem isn’t fixed. it’s just bypassed or masked over.

  • #11

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Category: Headlights