LMC Heavy Duty Headlight Harness - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Sinister · 12-23-2007, 01:18 PM

Anybody using the LMC Heavy Duty Headlight Harness? I wanted relays for my headlights but didn't want to hack up the stock wiring. Supposedly it's plug and play...

webbes · 12-23-2007, 01:58 PM

Works good in my truck so far but I just drove it last night 20 miles easy to install

Sinister · 12-23-2007, 02:06 PM

Cool, thanks webbes. Just ordered one as an X-mas gift to myself...

Hoss72 · 12-23-2007, 02:11 PM

Do they put out that much more light? I'm assuming you bought the Halogen Headlight. If they work good I will order some.

Sinister · 12-23-2007, 02:30 PM

I just ordered the harness with the relays, didn't get the halogens. I'm more concerned about the voltage going through the light switch and under dash harness.

webbes · 12-23-2007, 04:19 PM

Just order the harness for now. Still trying to get all the bugs out of my truck. Install a tpi motor in it. Working out good so far

Musclerodz · 12-23-2007, 05:37 PM

Harness is junk IMO, I bought a couple and they are cheaply made. Instructions are not even in English! AAW's relay kit is twice the price, but I feel it is twice the product, USA made and instructions in English.

Mike

72freak · 12-24-2007, 02:30 AM

Member "old yella" or "old yellow" has one

**LockDoc** · 12-24-2007, 04:37 AM

Quote:

Originally Posted by webbes

Still trying to get all the bugs out of my truck. Install a tpi motor in it. Working out good so far

webbes, do you have a build thread? I am in the process of installing a TPI/700r4 setup in my '70...

LockDoc

Andy4639 · 12-24-2007, 04:54 AM

Head light relays:
This has been a hot topic now for awhile. It seems to me to be a rather simple solution.
Buy two relays at NAPA or any other part store. Mount them close to the driver's side head light. Clip the two head light wires (low) & (high) about 6" away from the light. One end from the dash goes to the incoming switch terminal. The other end connects to the outgoing. Run a hot wire from battery and jump it off both relays. Connect a ground to both relays and your done. Typical wiring for a relay. I may even do this this weekend myself.

**FRENCHBLUE72** · 12-24-2007, 05:01 AM

I would not buy anything from L.M.C.

**Ricks1971** · 12-24-2007, 05:29 AM

I have been looking at these guys wiring harness.
http://www.americanautowire.com/FactoryFit.html

Rick

BLACK AND BLUE 67-72 · 12-24-2007, 05:59 AM

I don't understand, what the big deal is about upgrading the light system with relays when your running Halogen headlamps? I have been running Halogen headlights for 7 years now on my 72 Chevy and have never had 1 single problem with the headlight switch, wiring harness or dimmer switch.

**Stocker** · 12-24-2007, 06:14 AM

I have also run halogens for many years without a harness or relay, and no problems. However, I'm sure the voltage at the lamps -- and therefore the light output -- is less than optimal. I just haven't gotten around to verifying it with a meter...

Longhorn Man · 12-24-2007, 06:17 AM

black and blue, Even with old T3 bulbs, the relays set up is a good idea. You increase the power to the bulb, which increases the light output. This is a noticeable difference. Ever notice at night you can tell who has an old car on the freeway from a few miles away... the yellowish orange light conpaired to the white light?
The amount of amps going thought the switches is an issue too, but it's an issue over time. Even with old school non hallogon bulbs, the amps going through the switches burns them up over time.
I have done the conversion, and see no reason personally to buy a kit. Too many people are afraid to modify there harness. A good repair/upgrade is just as good as unmodified. It's when you have 7 connections in a single wire wrapped with duct tape and wire nuts... that's when there's a problem.

webbes · 12-24-2007, 07:54 AM

Lockdoc I do not but if you have any question just ask. I might be able to help
Bill

**LockDoc** · 12-24-2007, 08:51 AM

Quote:

Originally Posted by webbes

Lockdoc I do not but if you have any question just ask. I might be able to help
Bill

Thanks Bill. PM sent.

Sorry about the hijack... As a note on the OP's question, there's no doubt in my mind that the relay setup would take a lot of stress off of the light system, especially once the various connections start getting a little (or a lot) of corrosion on them. I know on a couple of older trucks I have had, after the lights have been on for a while the light switch under the dash got really hot. The relay mod should cure that. I plan on adding it to the white truck this spring.

LockDoc

LockDoc

Steelawork'n · 12-24-2007, 03:26 PM

Quote:

Originally Posted by Longhorn Man

black and blue, Even with old T3 bulbs, the relays set up is a good idea. You increase the power to the bulb, which increases the light output. This is a noticeable difference. Ever notice at night you can tell who has an old car on the freeway from a few miles away... the yellowish orange light conpaired to the white light?
The amount of amps going thought the switches is an issue too, but it's an issue over time. Even with old school non hallogon bulbs, the amps going through the switches burns them up over time.
I have done the conversion, and see no reason personally to buy a kit. Too many people are afraid to modify there harness. A good repair/upgrade is just as good as unmodified. It's when you have 7 connections in a single wire wrapped with duct tape and wire nuts... that's when there's a problem.

...Yeah, and do you get tired of your truck casting a shadow from the newer cars on your tail. Higher powered headlights give you road dominance at night.

BLACK AND BLUE 67-72 · 12-24-2007, 09:45 PM

Steelaworki'n, nope I don't have that problem as a matter of fact I get the newer cars flashing their lights at me when I have them on dim already (Yes they are adjusted properly) LOL. My headlights on my 72 are even brighter than my wife's 94 Ford Escort and her 93 Toyota Camry, I have absoultely no problem seeing at night with them they give off a very bright white light. Now compared to my 70 with the old T3 headlights (which looks like I am using two very dim flashlights) it is definitely a drastic change.

**WorkinLonghorn** · 12-24-2007, 10:14 PM

Real trucks have 4 headlights and don't need all this crap.

Andy4639 · 12-25-2007, 03:27 AM

WorkinLonghorn,

Quote:

Real trucks have 4 headlights and don't need all this crap.

That's why they had four light's to begin with they couldn't see!

Longhorn Man · 12-25-2007, 05:31 AM

try the real trucks, with 4 headlights, and relays.

I hit the high beams and I can see into next week.
Yeah, chicks dig it.

Andy4639 · 12-25-2007, 05:46 AM

Longhorn Man,

Quote:

try the real trucks, with 4 headlights, and relays. I hit the high beams and I can see into next week.
Yeah, chicks dig it.

How long after they get their eye sight back do they dig it!

**Stocker** · 12-25-2007, 05:49 AM

I've had 'em both ways and while four lamps outperform two on high beam (especially with position-specific E-codes!), the larger reflector & lens on 7" lamps will throw more light on low beam than a comparable 5 3/4" lamp.

Now, a 7" H-4 high/low with separate high beam lamps would be the best of both worlds...

Longhorn Man · 12-25-2007, 05:52 AM

LOL!!!
I prefer them slightly blinded... I can tell them I am real good looking and they won't question it. I tell them, "Picture brad pitt, but slightly better lookin and with a shaved head"
I have to blind them over and over sometimes.

12-23-2007, 01:18 PM	#1
Sinister Between Trucks... Join Date: Mar 2002 Location: Los Angeles, CA. Posts: 3,830	LMC Heavy Duty Headlight Harness Anybody using the LMC Heavy Duty Headlight Harness? I wanted relays for my headlights but didn't want to hack up the stock wiring. Supposedly it's plug and play... __________________ Beat it to fit, Paint it to match...

12-23-2007, 01:58 PM	#2
webbes Registered User Join Date: Oct 2005 Location: ILL. Posts: 129	Re: LMC Heavy Duty Headlight Harness Works good in my truck so far but I just drove it last night 20 miles easy to install __________________ 1970 4X4 LONG BED 350 TPI 700R4

12-23-2007, 02:06 PM	#3
Sinister Between Trucks... Join Date: Mar 2002 Location: Los Angeles, CA. Posts: 3,830	Re: LMC Heavy Duty Headlight Harness Cool, thanks webbes. Just ordered one as an X-mas gift to myself... __________________ Beat it to fit, Paint it to match...

12-23-2007, 02:11 PM	#4
Hoss72 Registered User Join Date: Oct 2007 Location: San Antonio TX Posts: 124	Re: LMC Heavy Duty Headlight Harness Do they put out that much more light? I'm assuming you bought the Halogen Headlight. If they work good I will order some.

12-23-2007, 02:30 PM	#5
Sinister Between Trucks... Join Date: Mar 2002 Location: Los Angeles, CA. Posts: 3,830	Re: LMC Heavy Duty Headlight Harness I just ordered the harness with the relays, didn't get the halogens. I'm more concerned about the voltage going through the light switch and under dash harness. __________________ Beat it to fit, Paint it to match...

12-23-2007, 04:19 PM	#6
webbes Registered User Join Date: Oct 2005 Location: ILL. Posts: 129	Re: LMC Heavy Duty Headlight Harness Just order the harness for now. Still trying to get all the bugs out of my truck. Install a tpi motor in it. Working out good so far __________________ 1970 4X4 LONG BED 350 TPI 700R4

12-23-2007, 05:37 PM	#7
Musclerodz Senior Member Join Date: Aug 2005 Location: OKC, OK Posts: 2,365	Re: LMC Heavy Duty Headlight Harness Harness is junk IMO, I bought a couple and they are cheaply made. Instructions are not even in English! AAW's relay kit is twice the price, but I feel it is twice the product, USA made and instructions in English. Mike __________________ Mike Redpath

12-24-2007, 02:30 AM	#8
72freak Rottenwood Garage Member Join Date: May 2005 Location: Marietta, Georgia Posts: 4,321	Re: LMC Heavy Duty Headlight Harness Member "old yella" or "old yellow" has one __________________ 2004 Chevrolet Suburban C1500 2001 Chevrolet 2500HD Crew 6.0 1999 Harley Davidson Electra Glide 1972 Chevrolet C-20 Custom Camper "Dump Truck" 1972 Chevrolet C-20 Suburban "Big Green" 1969 Chevrolet C-50 Wedge Hauler "Leonidis" 1966 C-10 2x4 short fleet 327 4 speed "Race Truck" 1952 Plymouth Cranbrook "Rican" (my grandfathers) 1931 Ford Model A Coupe "Black Beauty" 1930 Ford Model A truck "Club Cab" 4x4 Rottenwood Garage and Speed Shop.....where everything must be racy! *It's not just a hobby..It's a LIFESTYLE!!!* Thanks for nothing Barrett-Jackson You cant fix stupid or teach accountability! Time wasters, looky Lous and tire kickers are everywhere!

12-24-2007, 04:54 AM	#10
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,936	Re: LMC Heavy Duty Headlight Harness Head light relays: This has been a hot topic now for awhile. It seems to me to be a rather simple solution. Buy two relays at NAPA or any other part store. Mount them close to the driver's side head light. Clip the two head light wires (low) & (high) about 6" away from the light. One end from the dash goes to the incoming switch terminal. The other end connects to the outgoing. Run a hot wire from battery and jump it off both relays. Connect a ground to both relays and your done. Typical wiring for a relay. I may even do this this weekend myself. __________________ 1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs.

12-24-2007, 05:01 AM	#11
FRENCHBLUE72 PROJECT 7DEUCE Join Date: Dec 2002 Location: GRANTS PASS OR Posts: 21,608	Re: LMC Heavy Duty Headlight Harness I would not buy anything from L.M.C. __________________ GO BIG GREEN GO DUCKS MEMBER #6377 72 k-5 daily driver 6'' lift 35'' 350-350-205 slowly getting rust free. Project "7DEUCE" check out my build http://67-72chevytrucks.com/vboard/s...d.php?t=267665 Tim Powell..R.I.P EastSideLowlife..... R.I.P..

12-24-2007, 05:29 AM	#12
Ricks1971 Senior Member Join Date: Mar 2006 Location: Clarkrange Tennessee Posts: 1,786	Re: LMC Heavy Duty Headlight Harness I have been looking at these guys wiring harness. http://www.americanautowire.com/FactoryFit.html Rick

12-24-2007, 05:59 AM	#13
BLACK AND BLUE 67-72 Firefighter Join Date: Feb 2001 Location: Yellville, Ar, USA Posts: 1,943	Re: LMC Heavy Duty Headlight Harness I don't understand, what the big deal is about upgrading the light system with relays when your running Halogen headlamps? I have been running Halogen headlights for 7 years now on my 72 Chevy and have never had 1 single problem with the headlight switch, wiring harness or dimmer switch. __________________ '72 Chevy SWB 350 Auto '67 GMC LWB 350 4 speed '70 Chevy 4x4 Stepside 350 Auto Yellville, Ar. USA

12-24-2007, 06:14 AM	#14
Stocker 20' Daredevil (Ret) Join Date: May 2003 Location: Jefferson State Posts: 13,643	Re: LMC Heavy Duty Headlight Harness I have also run halogens for many years without a harness or relay, and no problems. However, I'm sure the voltage at the lamps -- and therefore the light output -- is less than optimal. I just haven't gotten around to verifying it with a meter... __________________ - Mike - 1972 K20 LWB 350/350/205 RIP El Jay

12-24-2007, 06:17 AM	#15
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: LMC Heavy Duty Headlight Harness black and blue, Even with old T3 bulbs, the relays set up is a good idea. You increase the power to the bulb, which increases the light output. This is a noticeable difference. Ever notice at night you can tell who has an old car on the freeway from a few miles away... the yellowish orange light conpaired to the white light? The amount of amps going thought the switches is an issue too, but it's an issue over time. Even with old school non hallogon bulbs, the amps going through the switches burns them up over time. I have done the conversion, and see no reason personally to buy a kit. Too many people are afraid to modify there harness. A good repair/upgrade is just as good as unmodified. It's when you have 7 connections in a single wire wrapped with duct tape and wire nuts... that's when there's a problem.

12-24-2007, 07:54 AM	#16
webbes Registered User Join Date: Oct 2005 Location: ILL. Posts: 129	Re: LMC Heavy Duty Headlight Harness Lockdoc I do not but if you have any question just ask. I might be able to help Bill __________________ 1970 4X4 LONG BED 350 TPI 700R4



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12-24-2007, 09:45 PM	#19
BLACK AND BLUE 67-72 Firefighter Join Date: Feb 2001 Location: Yellville, Ar, USA Posts: 1,943	Re: LMC Heavy Duty Headlight Harness Steelaworki'n, nope I don't have that problem as a matter of fact I get the newer cars flashing their lights at me when I have them on dim already (Yes they are adjusted properly) LOL. My headlights on my 72 are even brighter than my wife's 94 Ford Escort and her 93 Toyota Camry, I have absoultely no problem seeing at night with them they give off a very bright white light. Now compared to my 70 with the old T3 headlights (which looks like I am using two very dim flashlights) it is definitely a drastic change. __________________ '72 Chevy SWB 350 Auto '67 GMC LWB 350 4 speed '70 Chevy 4x4 Stepside 350 Auto Yellville, Ar. USA

12-24-2007, 10:14 PM	#20
WorkinLonghorn Senior Member Join Date: Dec 2006 Location: Studio City, Calif. Posts: 2,873	Re: LMC Heavy Duty Headlight Harness Real trucks have 4 headlights and don't need all this crap. __________________ '69 GMC C2500 Custom Camper, 8 1/2' bed, New GM 350, NP 435 Close Ratio 4spd. Trans., 3.73 Dana-60 open.Camper and Trailer wiring, PS, PB, AC, tach , three gas tanks, stereo speakers, 2nd owner, Work-Truck supreme.

12-25-2007, 05:31 AM	#22
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: LMC Heavy Duty Headlight Harness try the real trucks, with 4 headlights, and relays. I hit the high beams and I can see into next week. Yeah, chicks dig it.

12-25-2007, 05:49 AM	#24
Stocker 20' Daredevil (Ret) Join Date: May 2003 Location: Jefferson State Posts: 13,643	Re: LMC Heavy Duty Headlight Harness I've had 'em both ways and while four lamps outperform two on high beam (especially with position-specific E-codes!), the larger reflector & lens on 7" lamps will throw more light on low beam than a comparable 5 3/4" lamp. Now, a 7" H-4 high/low with separate high beam lamps would be the best of both worlds... __________________ - Mike - 1972 K20 LWB 350/350/205 RIP El Jay

12-25-2007, 05:52 AM	#25
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: LMC Heavy Duty Headlight Harness LOL!!! I prefer them slightly blinded... I can tell them I am real good looking and they won't question it. I tell them, "Picture brad pitt, but slightly better lookin and with a shaved head" I have to blind them over and over sometimes.

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