Headlight relay

[skokie]

I was reading this post http://67-72chevytrucks.com/vboard/s...highlight=horn and have put this on the list of things to do to my truck. Saw this on lmc truck https://www.lmctruck.com/1967-72-che...dlight-harness

Has anyone used the one from LMC?

[Steeveedee]

I got mine from there. It's working fine, so far. It's been about 1.5 years since installation.

[72SB]

Yes, same as mine. Here is my thread about it

https://67-72chevytrucks.com/vboard/...dlight+harness

Makes not only headlights brighter, but all other lights also

[skokie]

Originally Posted by 72SB

Yes, same as mine. Here is my thread about it

https://67-72chevytrucks.com/vboard/...dlight+harness

Makes not only headlights brighter, but all other lights also

Thanks for the post. How did you tap into the headlight wires? Is there connectors that come with it etc? Do you have more pics of the installation?

Thanks!

[72SB]

Install is very simple. No cutting any wires. Just mount the relays where I did or on PS of core support if you want. Simple install steps come with harness

Mount relays (I drilled 2 holes in fender lip)
connect harness + wire to the + buss on PS fender by battery
screw ground wire to fender
unplug PS headlight and plug it into harness (marked plug)
plug the harness plug into PS headlight
run harness under core support to DS
Unplug DS headlight (it will be left unused)
plug harness plug into DS headlight

Open beer, admire work

I have one of these in my 67 Camaro also (different brand). All the older cars had full headlight draw go through the switch, so this mod is beneficial to any car/truck of that era

[MARKDTN]

These kits are great. I would find one that has the following: at least 2 relays, 1 for high beam and 1 for low beam. Real high quality 5-pin relays made by Bosch, Hella, or Tyco. No offshore China relays (sealed Delco oval relays would also be acceptable-but not square). Actual real relay sockets, if it just has female spades for the relays, pass. Would be nice if the sockets had a mounting tab. Good quality wire and nice loom. Be sure to create a rock-solid ground. You are replacing-or at least supplementing-the factory ground for the headlights with this harness. If you do that you should have something that will last another 50 years.

[skokie]

Originally Posted by MARKDTN

These kits are great. I would find one that has the following: at least 2 relays, 1 for high beam and 1 for low beam. Real high quality 5-pin relays made by Bosch, Hella, or Tyco. No offshore China relays (sealed Delco oval relays would also be acceptable-but not square). Actual real relay sockets, if it just has female spades for the relays, pass. Would be nice if the sockets had a mounting tab. Good quality wire and nice loom. Be sure to create a rock-solid ground. You are replacing-or at least supplementing-the factory ground for the headlights with this harness. If you do that you should have something that will last another 50 years.

I have been bitten by offshore stuff before. I am thinking about piecing something together and make my own harness. Thanks again!

[72SB]

I wish there was one of these harness that is made in USA, maybe there is.

The one I got for my Camaro from Speedway was in a plastic zip loc bag, no printed instructions but these things are frankly self-describing on how to install. I assume someone made the Speedway one here....but were "offshore" parts used, IDK.

So far, for me both the Speedway one and the LMC one (which is clearly packaged as being from China) are working. YMMV

[RichardJ]

Those kits seem to be nice, but you are adding 20 feet of extra wires around the radiator support. I added one 12 v wire from the battery junction block across to the driver side fender. I wired the relays like was described in the first post of the link provided by the OP in this thread. Less complicated and far fewer excess wires.

[72SB]

^^??

well a few ways to skin this cat, rolling your own setup is fine

Not sure about your 20' math of extra wiring....

with a harness pre-made you are capturing the high volt, 12vdc, from the buss terminal on PS fender next to battery so that eliminates it coming all the way from the headlight switch to both L&R headlights but the wire running across the core support, IMHO is shorter overall of the 2 eliminated from headlight switch

IMHO either way a non-issue which method you chose. The main reason is to relieve the full draw load of headlights from the headlight switch itself and turning it into a relay trigger to activate the buss bar +12vdc source for headlights

[RichardJ]

It looks like 20 feet to me and this is just for a two light chevy.
The other link in the first post for LMC shows the guy removing the battery, battery box and loosening the radiator. In the end, they ended up with the battery wiring in the screen capture shown below.

Sorry, I don't want any of that.

[Already Gone]

With my first truck I went to the junk yard and gota couple realys froman old Dodge Caravan and with Instructions from MAD Electricals site and did the headlight upgrade bt this time I bought the American Autowre Kit, in 2018, and havent installed it yet.

https://www.americanautowire.com/sho...ncer-relay-kit

[72SB]

Originally Posted by RichardJ

It looks like 20 feet to me and this is just for a two light chevy.
The other link in the first post for LMC shows the guy removing the battery, battery box and loosening the radiator. In the end, they ended up with the battery wiring in the screen capture shown below.

Sorry, I don't want any of that.

I would never do a hack install like the one shown in the pic of the LMC one you posted. Never connect an AUX lead wire to main battery post. Use the + Buss on the fender next to battery.....typically a good + battery cable has an AUX wire that feeds this aux buss and are themselves a fusible 30amp link

I did remove the 2 radiator hold down brackets to run the harness in the core support but never had to move the radiator itself. Removing battery makes it easier to unplug PS headlight and access the AUX buss connection

These headlight relay harnesses are very simple, and one can make their own. AAW stuff, IMHO, is always solid stuff. There are also a few independent "wire guys" who make this stuff. Gary @ innovative wiring makes great stuff. IDK if he does make headlight harness but his (battery cables, EL fan relay harness, MAF extensions, etc) are excellent quality

[1971Stepside]

If one springs for the Holley retro headlights do those need this relay option?

[72SB]

Originally Posted by 1971Stepside

If one springs for the Holley retro headlights do those need this relay option?

a relay harness will benefit any lamp type used...with that said the Holly LED's are quite bright

[Southcity]

Originally Posted by 1971Stepside

If one springs for the Holley retro headlights do those need this relay option?

No relay required when running any LED headlight. I've tested this on my two Suburbans with Holley/Retrobrights and United Pacific. One with relay, one without, no change in LED light brightness or performance.

If running stock headlights or H4 upgrade, relay setup is highly recommended.
It's worth mentioning that the relay setup does take the load off the headlight switch so regardless which headlight you run (stock, H4 or LED), it's an upgrade.

[skokie]

Originally Posted by Southcity

No relay required when running any LED headlight. I've tested this on my two Suburbans with Holley/Retrobrights and United Pacific. One with relay, one without, no change in LED light brightness or performance.

If running stock headlights or H4 upgrade, relay setup is highly recommended.
It's worth mentioning that the relay setup does take the load off the headlight switch so regardless which headlight you run (stock, H4 or LED), it's an upgrade.

What kind of LED headlights are you running?

Thanks!

[Southcity]

K10 = Holley Retrobright
GMC = United Pacific

Both perform great but I'm liking the Retrobrights for their stock-lens look

[biketopia]

Originally Posted by Southcity

K10 = Holley Retrobright
GMC = United Pacific

Both perform great but I'm liking the Retrobrights for their stock-lens look

Shooo for $200 EACH I'd try a pair of conversion lenses and some amazon or ebay LED bulbs 3 or 4 times over. I'm sure they're nice, but $400 for headlights is a bit much.
https://www.amazon.com/IPCW-CWC-7006...01OMEPEU&psc=1

[Wrenchbender Ret]

Halogens became popular in the early to mid 80's.
I can't see any advantage to using relays with LED lamps.
George

[biketopia]

Originally Posted by Wrenchbender Ret

Halogens became popular in the early to mid 80's.
I can't see any advantage to using relays with LED lamps.
George

Some LED set up's pull decent amperage. Mainly in headlight applications, some sort of load to build up heat is used to help keep them from fogging or icing up in poor weather conditions.

[skokie]

Thanks for the ideas. I will look into both the LED headlights and the relay conversion.
This is why this board is AWESOME!!

[mrein3]

Originally Posted by Stocker

Nope, just the old standard sealed-beam headlamps. Not sure when halogen bulbs became the norm.

I wore glasses from age 7 until I got contacts at 19. Since cataract surgery several years ago, I now just use readers. Improved lighting has always been a good thing for me, no matter my age or vision correction.

Originally Posted by Wrenchbender Ret

Halogens became popular in the early to mid 80's.
I can't see any advantage to using relays with LED lamps.
George

Originally Posted by biketopia

Some LED set up's pull decent amperage. Mainly in headlight applications, some sort of load to build up heat is used to help keep them from fogging or icing up in poor weather conditions.

Originally Posted by skokie

Thanks for the ideas. I will look into both the LED headlights and the relay conversion.
This is why this board is AWESOME!!

FWIW, if you install a relay system into your headlight circuit you really don't need trick headlights. I'm running halogens with a relay system I rolled myself.

When you install one of these kits or roll your own all you are doing is turning your headlight switch into a relay controller. This has two benefits.

First you get a good 14+ volts (engine running) to each headlight straight off the battery where the stock system only gets around 10.8 or so volts to each headlight. Before you install your system measure the voltage at the headlight. You're going to be surprised at what is there.

Second thing is all that current drop has to go somewhere. It is turned into heat. This heat is what takes out your headlight switch. By installing relays to run current directly from the battery you are done replacing headlight switches which get killed from the heat generated from the voltage drop between the switch and the headlights.

Think about it. In a stock system, you have current running from the battery, into the cab, to the headlight switch, to the dimmer on the floor, then out to the headlights. With one of these relay kits the headlight switch tells the relay to turn on the wire from the battery to the headlight.

If you're simply looking for brighter headlights, install one of these kits or roll your own. Drive it at night like that for a while then decide whether $200 headlights are worth it. In this economy I'm guessing you are going to put that $200 light idea on the back burner for a while.

[OregonNed]

Installed this wiring kit a couple of years ago - pleased with how it turned out. I do keep a couple of extra relays in the glove box just in case.

[72SB]

^^^ spot on advice