Question for GMC guys + headlights - The 1947 - Present Chevrolet & GMC Truck Message Board Network

JoetheMobster · 09-13-2003, 10:10 PM

I was curious if anyone has changed the 4 headlight setup from 2high/2low beam to 4 high/low beams?? Is it possible with stock wiring, and not frying any wiring/switches etc.?

If you read this Zurbo - thanks for making me curious!!

JoetheMobster · 09-13-2003, 11:52 PM

Nobody huh

krue · 09-14-2003, 12:01 AM

Man my lights are wicked bright with just two of them bright!

*Phillip Johnson* · 09-14-2003, 12:09 AM

Ive changed a 4 headlight GMC to a 2 headlight CHEVY! So much nicer to look at, in my opinion!

Maximum Overdrive · 09-14-2003, 12:32 AM

I havent done it on mine. It seems it would be easy enough to do though.

*dtlilly* · 09-14-2003, 01:38 AM

I was thinking of trying to convert to a 2 low 4 high system, but I guess it's more of an arm chair idea

jay6891 · 09-14-2003, 08:18 AM

I don't think that you could go to a 4 low/4high. Unless I'm thinking wrong. with all 4 on it would always be on bright. Seeing how its not a brighter bulb for brights, its the angle that they are sitting in the bezel and where they are aimed.

**FRENCHBLUE72** · 09-14-2003, 09:54 AM

I am sure it would be pretty easy to do and be legal still. They make a kit for 89 and up chevy's that let all four light's be on..

Longhorn Man · 09-14-2003, 10:45 AM

If you want all 4 headlights to be on while on low beam, then it would not be legal.It could be done pretty easily though.
If you want brighter headlights, first step would be cleaning your grounds real good. I did this on Jewels's truck and it made a huge differance. Some new hallogen headlamps would be a good next step, as would be double checking your head light aim.
I have done all that, and my head lamps are qute bright. However, I want them to be new car bright, so I am going to wire them up with a couple relays.
It is pretty easy to do, here is a link I have found that lays it all out for you. http://www.classictruckshop.com/club...ead/lights.htm
This really does make the differance of night and day. As your truck is now, you may be getting as little as 10 - 11 volts to your headlams. With the relay, you'll get more like 13 to 13.5.

Green72GMC · 09-14-2003, 02:16 PM

Quote:

Originally posted by dtlilly
I was thinking of trying to convert to a 2 low 4 high system, but I guess it's more of an arm chair idea

All 4 of yours aren't already on when you have high beams on?

*dtlilly* · 09-14-2003, 02:21 PM

Unfortunately not. They were wired by the perverbial dope smoking old man (no not me

)

Low beam = two outer lights
High beam = two inner lights

Green72GMC · 09-14-2003, 02:23 PM

Oh, because all 4 of mine are on when I have High beams on. and 2 when its on low beams.

*dtlilly* · 09-14-2003, 02:31 PM

My truck wiring is a fire waiting to happen. With all the old wires, and the new wires spliced together, I'm lucky anything works.

I have a Haywire wire kit, just waiting for the time/money to begin the resto. Sounds like I'll need to pull some connectors off a junk truck to get the lights working right.

Figment412 · 09-14-2003, 04:51 PM

I have thought about using one set for high low beams and putting some high performance lights in for off-roading.

*dtlilly* · 09-14-2003, 05:34 PM

I read on the board awhile back about using aircraft landing gear lights for the inside lights. That would look pritty neat too

Longhorn Man · 09-14-2003, 06:40 PM

Quote:

Originally posted by Figment412
I have thought about using one set for high low beams and putting some high performance lights in for off-roading.

Actually, you may want to look into your local laws on that one too. I know here that is a no-no.

jewels. · 09-14-2003, 06:46 PM

Quote:

Originally posted by Longhorn Man
If you want all 4 headlights to be on while on low beam, then it would not be legal.It could be done pretty easily though.
If you want brighter headlights, first step would be cleaning your grounds real good. I did this on Jewels's truck and it made a huge differance. Some new hallogen headlamps would be a good next step, as would be double checking your head light aim.

Longhorn is correct! If your problem is dim headlights, don't rewire them to four headlights, just fix the headlights you have. Try re-grounding them. Then, change out the lamps with some new halogens. We did this to my truck (thanks longhorn!), and boy, I can see miles now!

good luck!

jewels.

GMC Jim · 09-16-2003, 12:48 AM

The GMC 4 headlite system uses the PAR 46 bulb ( 5.7" diameter). Original lamps were outer lamps; #4000 hi/lo beam @ 37.5/60.0 watts. Inner lamps were #4001 hi beam @ 37.5 watts.
This combo produced :- Hi beam ( 4 lites on) total wattage 150 ( 37.5 X 4 = 150). Lo Beam ( outer lites on) total wattage 120. (60 X 2= 120)
The charts list halogen lamps as replacements. Outer lamps ( lo-beam) #H5006 35.0/35.0 watts. Inner lamps (hi-beam) #H5001 50.0 watts. This will give a total wattage for hi beams of 170 and a total wattage for lo-beams of 70. This lo beam wattage is actually a downgrade compared to the original configuration !!! ( the original #4001 is no longer available)
I configured my headlite system using # 4000 (37.5/60.0 watts) for the outer lites. The inner lites are #H5001 (50.0 watts). This combination give a total of 175 watts for hi-beam and 120 watts for lo beam; an improvement over the original.
Also, installed relays and 12 gauge wiring to the headlites which ; as Longhorn Man states, supplies about 13.4 volts to the lites.. Have been quite pleased with this conversion......Jim

09-13-2003, 10:10 PM	#1
JoetheMobster Listening since '86 Join Date: Sep 2001 Location: Canada Posts: 1,799	Question for GMC guys + headlights I was curious if anyone has changed the 4 headlight setup from 2high/2low beam to 4 high/low beams?? Is it possible with stock wiring, and not frying any wiring/switches etc.? If you read this Zurbo - thanks for making me curious!! __________________ 2007 Saturn Aura - hey it WAS a GM product

09-13-2003, 11:52 PM	#2
JoetheMobster Listening since '86 Join Date: Sep 2001 Location: Canada Posts: 1,799	Nobody huh __________________ 2007 Saturn Aura - hey it WAS a GM product

09-14-2003, 12:01 AM	#3
krue Designated A-hole! Join Date: Mar 2003 Location: South Mississippi Posts: 36,450	Man my lights are wicked bright with just two of them bright! __________________ "If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck"

09-14-2003, 12:32 AM	#5
Maximum Overdrive December 21, 2012 Join Date: Apr 2000 Location: Black Eagle, Montana Posts: 1,634	I havent done it on mine. It seems it would be easy enough to do though. __________________ *"!Ama Sua, Ama Kjella, Ama Lllulla!"*

09-14-2003, 08:18 AM	#7
jay6891 Car Knocker Join Date: May 2001 Location: jefferson,arkansas Posts: 664	I don't think that you could go to a 4 low/4high. Unless I'm thinking wrong. with all 4 on it would always be on bright. Seeing how its not a brighter bulb for brights, its the angle that they are sitting in the bezel and where they are aimed. __________________ 68 c-10,91 sportside bed,350 .030 over,4 bolt,10-1 comp,2.05 intake/1.94 exhaust,1.6 Harland Sharp roller rockers,edelbrock rpm cam and intake w/750 carb, 700r4, 3.73 gears,Jacabbs Electronic Igntion w/Accel HEI distributer and super coil. ZR-1 roll pan, filled tailights. Blazer tank. Hidden hitch. 2 1/2" Flowmaster 40's. Parts bought but not installed>> ford 9" posi with disc. CCP front and rear lowering kit 4/5. Cab corners,foor boards,rockers, cab braces, Phatom grill, Painless wiring kit.

09-14-2003, 12:09 AM	#4
Phillip Johnson Account Suspended Join Date: Apr 2000 Location: Grants Pass, Oregon Posts: 1,580	Ive changed a 4 headlight GMC to a 2 headlight CHEVY! So much nicer to look at, in my opinion!

09-14-2003, 01:38 AM	#6
dtlilly Account Suspended Join Date: Jan 2003 Location: Shadow of Lambeau Field Posts: 5,597	I was thinking of trying to convert to a 2 low 4 high system, but I guess it's more of an arm chair idea

09-14-2003, 09:54 AM	#8
FRENCHBLUE72 PROJECT 7DEUCE Join Date: Dec 2002 Location: GRANTS PASS OR Posts: 21,608	I am sure it would be pretty easy to do and be legal still. They make a kit for 89 and up chevy's that let all four light's be on.. __________________ 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..

09-14-2003, 10:45 AM	#9
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	If you want all 4 headlights to be on while on low beam, then it would not be legal.It could be done pretty easily though. If you want brighter headlights, first step would be cleaning your grounds real good. I did this on Jewels's truck and it made a huge differance. Some new hallogen headlamps would be a good next step, as would be double checking your head light aim. I have done all that, and my head lamps are qute bright. However, I want them to be new car bright, so I am going to wire them up with a couple relays. It is pretty easy to do, here is a link I have found that lays it all out for you. http://www.classictruckshop.com/club...ead/lights.htm This really does make the differance of night and day. As your truck is now, you may be getting as little as 10 - 11 volts to your headlams. With the relay, you'll get more like 13 to 13.5.

09-14-2003, 02:21 PM	#11
dtlilly Account Suspended Join Date: Jan 2003 Location: Shadow of Lambeau Field Posts: 5,597	Unfortunately not. They were wired by the perverbial dope smoking old man (no not me ) Low beam = two outer lights High beam = two inner lights

09-14-2003, 02:23 PM	#12
Green72GMC Registered User Join Date: Apr 2003 Location: Deville, Louisiana Posts: 293	Oh, because all 4 of mine are on when I have High beams on. and 2 when its on low beams. __________________ 1972 GMC SWB, 305 powered 1980 diesel VW pickup, Needs a Heart Transplant 1997 Toyota Taco The Second Amendment is in place incase they ignore the others.

09-14-2003, 02:31 PM	#13
dtlilly Account Suspended Join Date: Jan 2003 Location: Shadow of Lambeau Field Posts: 5,597	My truck wiring is a fire waiting to happen. With all the old wires, and the new wires spliced together, I'm lucky anything works. I have a Haywire wire kit, just waiting for the time/money to begin the resto. Sounds like I'll need to pull some connectors off a junk truck to get the lights working right.

09-14-2003, 04:51 PM	#14
Figment412 Registered User Join Date: Dec 2002 Location: Fort Wayne, IN Posts: 108	I have thought about using one set for high low beams and putting some high performance lights in for off-roading. __________________ Save your money and do it right the first time. 1968 GMC short bed 1972 Cab 74 SB Chevy running gear

09-14-2003, 05:34 PM	#15
dtlilly Account Suspended Join Date: Jan 2003 Location: Shadow of Lambeau Field Posts: 5,597	I read on the board awhile back about using aircraft landing gear lights for the inside lights. That would look pritty neat too

09-16-2003, 12:48 AM	#18
GMC Jim Senior Member Join Date: Dec 2002 Location: Portland, Oregon Posts: 901	The GMC 4 headlite system uses the PAR 46 bulb ( 5.7" diameter). Original lamps were outer lamps; #4000 hi/lo beam @ 37.5/60.0 watts. Inner lamps were #4001 hi beam @ 37.5 watts. This combo produced :- Hi beam ( 4 lites on) total wattage 150 ( 37.5 X 4 = 150). Lo Beam ( outer lites on) total wattage 120. (60 X 2= 120) The charts list halogen lamps as replacements. Outer lamps ( lo-beam) #H5006 35.0/35.0 watts. Inner lamps (hi-beam) #H5001 50.0 watts. This will give a total wattage for hi beams of 170 and a total wattage for lo-beams of 70. This lo beam wattage is actually a downgrade compared to the original configuration !!! ( the original #4001 is no longer available) I configured my headlite system using # 4000 (37.5/60.0 watts) for the outer lites. The inner lites are #H5001 (50.0 watts). This combination give a total of 175 watts for hi-beam and 120 watts for lo beam; an improvement over the original. Also, installed relays and 12 gauge wiring to the headlites which ; as Longhorn Man states, supplies about 13.4 volts to the lites.. Have been quite pleased with this conversion......Jim __________________ '71 GMC;fleetside;PB/PS/AC/CC/402 Eng./Custom Paint/110,000act miles/3 fuel tanks(52gal).



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