Headlight harness upgrade and modification to 4 highbeams

[hinkv10]

I bought this headlight upgrade 7 months ago from lmc for $30 and finally installed it after I fixed my high beam switch. I am familiar with this type of setup from an upgrade to a *** bike I did. It is pretty simple and everything is labeled in English and Chinese.

Normally current goes thru the headlight switch and then to the bulbs. Not a big deal if you are using led's or hid's but with halogen every watt counts and the longer trip eats away some of your brightness. This plugs into 1 low beam plug of your existing wiring. Hook up grounds and power and then your 4 plugs and you are done. Took maybe 20 minutes mostly because I had to take the battery out and drill holes for the grounds.

It is a definite improvement and when I turned on high beams, all 4 bulbs stay on. Added bonus for those of u wanting to do that mod.

 

[chengny]

It is a definite improvement and when I turned on high beams, all 4 bulbs stay on. Added bonus for those of u wanting to do that mod.


Anyone care to discuss this? There seems to be a lot of misunderstanding about how the quad headlights system operates.

I think that they operate like this:

When the dimmer is in the low beam position, only the lower wattage filament in the upper sealed beam is energized. They look like this:

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When the high beams are selected, the higher wattage filament in the uppers and the single filament in the lowers is energized and they look like this:

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The wiring diagrams I have would seem to agree. This one shows the headlights in "low beam" mode. Power is only to the upper sealed beam and is supplied by the tan wire:

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When switched to "high beam" mode, the dimmer switch de-energizes the tan wire and energizes the light green wire. The light green wire feeds the lower sealed beam and the alternate filament in the upper sealed beam:

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But then, I read many posts on this subject where people say they want to have both the high and low sealed beam lit up when the highs are selected. Don't they already do that?

And to confuse the issue further, I read this in the GM service manual:

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Does anyone have an unaltered, stock truck equipped with quad headlights. If they do, could they go out and take pictures of the headlights in both the high and low beam modes?

 

[GTME94]

Mine is pretty stock as far as I know. I'll check it out tomorrow and reply. If I remember correctly you are right Jerry.

 

[MadOgre]

It is a definite improvement and when I turned on high beams, all 4 bulbs stay on. Added bonus for those of u wanting to do that mod.


Anyone care to discuss this? There seems to be a lot of misunderstanding about how the quad headlights system operates.

I think that they operate like this:

When the dimmer is in the low beam position, only the lower wattage filament in the upper sealed beam is energized. They look like this:

You must be registered for see images attach

When the high beams are selected, the higher wattage filament in the uppers and the single filament in the lowers is energized and they look like this:

You must be registered for see images attach

The wiring diagrams I have would seem to agree. This one shows the headlights in "low beam" mode. Power is only to the upper sealed beam and is supplied by the tan wire:

You must be registered for see images attach

When switched to "high beam" mode, the dimmer switch de-energizes the tan wire and energizes the light green wire. The light green wire feeds the lower sealed beam and the alternate filament in the upper sealed beam:

You must be registered for see images attach

But then, I read many posts on this subject where people say they want to have both the high and low sealed beam lit up when the highs are selected. Don't they already do that?

And to confuse the issue further, I read this in the GM service manual:

You must be registered for see images attach

Does anyone have an unaltered, stock truck equipped with quad headlights. If they do, could they go out and take pictures of the headlights in both the high and low beam modes?

You know I went and double checked mine after reading the OP. Mine are stock for a fact, never been altered and my quad headlights are all on in high beam mode. and the low beam light seems brighter in high beam as well.

So im not sure what the need for the wiring kit is unless its a more efficient way of wiring it somehow. ?

 

[flyboy1100]

I plan to add relays to my setup, but all 4 lights are on from the factory so there is no need to mess with that part.



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[chengny]

Thanks guys.

I am currently switching a 2 HL truck to quads. And before starting the harness conversion, I just wanted to be sure of the basics. I thought I remembered my old black truck (bone stock with quads) worked like that.

MadO - this is correct:

and the low beam light seems brighter in high beam as well.

The upper sealed beam has two filaments (60W & 40W). When in low beam mode, only the 40W filament is energized. When switched to high beams, power to the 40W is shut off and the 60W filament is energized.

The lower sealed beam has just one filament (50W) and it is only energized in high beam mode.

So when on high beams, the uppers are actually 10 watts brighter than the lows.

 

[MadOgre]

Thanks guys.

I am currently switching a 2 HL truck to quads. And before starting the harness conversion, I just wanted to be sure of the basics. I thought I remembered my old black truck (bone stock with quads) worked like that.

MadO - this is correct:

and the low beam light seems brighter in high beam as well.

The upper sealed beam has two filaments (60W & 40W). When in low beam mode, only the 40W filament is energized. When switched to high beams, power to the 40W is shut off and the 60W filament is energized.

The lower sealed beam has just one filament (50W) and it is only energized in high beam mode.

So when on high beams, the uppers are actually 10 watts brighter than the lows.

Good to know. By the way Peterbilts use the same set up. same bulbs

You should post that 2 to 4 conversion. I have been looking at a project that I might want to do that to as well.

Its a lot easier tackling or even deciding to tackle a project when you know what your up against.

 

[chengny]

The wiring modifications are not that involved - if you decide to go that route. I don't do it that way. I find the best bet is to hunt down a truck with quads in the junkyard and surgically remove the harness.

These are the major components that need to be changed:

1. The radiator support - must be specifically for quads. It will have two circular openings. Like this:

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2. The grille mounts to the quad style radiator frame and has the parking lights behind the fins:

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3. A pair of quad bezels:

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4. Buckets (each one is different), sealed beams and retaining rings. Classic sells the complete assembly for $28 - aftermarket:

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5. Mounting springs, adjusting screws and nuts for sealed beam assemblies

6. Misc screws

The good news is that the chrome trim around the grille and bezels is the same for both quads and dual headlight setups.

 

[hinkv10]

Ok I guess the "added bonus" is just it working as designed. I"ve had other vehicles that it was one or the other, maybe my 69 Cutlass but anyways. I thought I read a post on here of somebody who wanted both bulbs on while using high beams.

The purpose of the harness is to provide direct current from the battery to the lights without going thru the headlight switch and all associated wiring. I upgraded the low beams to Sylvania something or other last year but left the high beams with the el cheapo bulbs that were in it because I could hardly use the high beams.

I would guess its about 15% brighter and it makes a huge difference when the highbeams are on. I had a similar setup on a Kawasaki motorcycle, single bulb and had similar results.

 

[MadOgre]

The wiring modifications are not that involved - if you decide to go that route. I don't do it that way. I find the best bet is to hunt down a truck with quads in the junkyard and surgically remove the harness.

These are the major components that need to be changed:

1. The radiator support - must be specifically for quads. It will have two circular openings. Like this:

You must be registered for see images attach

2. The grille mounts to the quad style radiator frame and has the parking lights behind the fins:

You must be registered for see images attach

3. A pair of quad bezels:

You must be registered for see images attach

4. Buckets (each one is different), sealed beams and retaining rings. Classic sells the complete assembly for $28 - aftermarket:

You must be registered for see images attach

5. Mounting springs, adjusting screws and nuts for sealed beam assemblies

6. Misc screws

The good news is that the chrome trim around the grille and bezels is the same for both quads and dual headlight setups.

I have to go and look again now lol I have about the shortest memory possible.

So the whole harness disconnects at the fuse block in the firewall ?

I wasn't sure how that connection of the harness works from one to the other ?

 

[MadOgre]

Ok I guess the "added bonus" is just it working as designed. I"ve had other vehicles that it was one or the other, maybe my 69 Cutlass but anyways. I thought I read a post on here of somebody who wanted both bulbs on while using high beams.

The purpose of the harness is to provide direct current from the battery to the lights without going thru the headlight switch and all associated wiring. I upgraded the low beams to Sylvania something or other last year but left the high beams with the el cheapo bulbs that were in it because I could hardly use the high beams.

I would guess its about 15% brighter and it makes a huge difference when the highbeams are on. I had a similar setup on a Kawasaki motorcycle, single bulb and had similar results.

Does anyone have a wiring schematic of the improved wiring, drawing directly from the battery ?

 

[flyboy1100]

http://www.danielsternlighting.com/tech/relays/relays.html

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[MadOgre]

http://www.danielsternlighting.com/tech/relays/relays.html

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Cool link Thanks. Seems after reading that, its maybe not a bad idea to pick up the upgraded wiring kit like the one from lmc ?

 

[MadOgre]

Im not sure where a good place would be to find the right relays, on there own ?

I have bad luck with parts guys. I usually end up getting mad at them and then having to show them where to find it in there own books.

 

[chengny]

Just use an off the shelf Bosch 4 or 5 pin relay. Get them with a mounting tab - it makes the job so much easier:

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Control wiring is on 85/86 and the load is across 30/87.

Advance has a 40 amp general purpose relay from Optronics that does the same thing - for $5.49:

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