I made GMC Headlite Diagram - The 1947 - Present Chevrolet & GMC Truck Message Board Network

*aquik72gmc350* · 08-31-2005, 05:48 PM

I made a GMC version of the headlite w/ relays. It uses 4 relays, 2 for headlites, and 2 for high beams. Next I'm working on doing my reverse lights, and brake/turn lights.

Rakort · 08-31-2005, 11:42 PM

Quote:

Originally Posted by aquik72gmc350

I made a GMC version of the headlite w/ relays. It uses 4 relays, 1 for each headlite, and 1 for each high beams. Let me know if you see anything wrong with it. EDIT: I'M GOING TO CHANGE SOME THINGS ON IT.

Umm, I don't see anything?

My thought is 6 realys sounds like a lot when you probably do it with two.

70GMCer · 09-01-2005, 05:56 AM

where do you tie in the battery voltage and where is the wiring for the headlight switch? Maybe it's all there looking at me, just not labeled...........

67chevemall · 09-01-2005, 08:10 AM

That is one cool avatar^^^ How much more will it go? Government mobsters suck!

force you to break the law. got weed?

sargentjones · 09-01-2005, 08:55 AM

who knows chief. a buck 13 a liter ain't high enough. Give er time bud, sh'll hit 2 in no time

dime bags, dime bags....
get yer dime bags here:::::::::::

smokekiki · 09-01-2005, 09:56 AM

Quote:

Originally Posted by 70GMCer

where do you tie in the battery voltage and where is the wiring for the headlight switch? Maybe it's all there looking at me, just not labeled...........

The Brown angd the Green wires are coming from the switch,The reds are power,on this diagram

sneakysnake · 09-01-2005, 01:07 PM

You have your low beam stock wire energizing you high beam relays
and vise versa. Nice schematic.

68C15 · 09-01-2005, 02:01 PM

I see a couple of problems. the low bulbs in your diagram have the brown going to gnd. it should be fed power fromthe low relays. the green should feed both high & low bulbs. also one relay for high 7 another for low is sufficient. thats what I have on mine. using relays for the tail & brake-turn is a wasye of time & money. they dont draw enough current to warrant a relay. I agree though that the headlights being fed from a relay is a good idea. that way the light switch doesnt have to carry the load & there is more voltage at the bulbs.

*aquik72gmc350* · 09-01-2005, 08:47 PM

I'm kinda confused now. I marked each wire with a number. Can you tell me which ones are incorrect and what to change it to? Thank-you

sneakysnake · 09-01-2005, 09:43 PM

OK, #5 stock wire should go to coil of the low beam relay
and the #4 stock high should go to the coil of the high relay.

Othe bulbs "68c15" mentioned are color coded wrong,the BROWN should be your power wire from the low relay and BLACK should be the ground.
in other words #1 should be brown and chas grnd should be black.

On a low beam light bulb you have three prongs one is ground one is low filament and the other is a high.
A high beam bulb only has two prongs hot and ground
So on your diagram you dont really need four relays,but if you insist.LOL
then the two low relays should feed one prong on each low beam bulb.
and the high relays should feed the high bulbs plus the other prong of the low beam bulbs.
Hope that makes sense, your on the right track just need to tweek it a little

68C15 · 09-01-2005, 10:08 PM

Give Me A Few Minutes & I Will Try To Rework The Diagram For You

68C15 · 09-01-2005, 10:28 PM

I tried to re-do it on my computer with no luck. probably the best thing to do is call me after 8:30 Fri night (central time) & I will grab my diagram from work & walk you through it. look for a PM with my phone #.
at this moment I dont remeber if the factory is green or tan for the low beams.
PS, there is a way to do this with just one relay but it is somewhat complicated.

sneakysnake · 09-01-2005, 11:43 PM

heres a crude version to go by,dont laugh.LOL

Project1970 · 09-02-2005, 01:28 AM

Yeah, also, there's no reason to need 4 relays. The brightest bulbs are what, 100W? 100W / 12V = about 8.3A per bulb. Those Bosch relays should be able to handle 30A with ease, and 16A should be no problem.

68C15 · 09-02-2005, 07:37 AM

Quote:

Originally Posted by sneakysnake

heres a crude version to go by,dont laugh.LOL

so just when did you pop my hood & check out my wiring?
did you see the way I converted over to an IR alternator?

<in other words sneakysnake has hit the nail on the head & saved you a call>

09-01-2005, 05:56 AM	#3
70GMCer Senior Member Join Date: Apr 2005 Location: Joppa, Maryland Posts: 4,408	where do you tie in the battery voltage and where is the wiring for the headlight switch? Maybe it's all there looking at me, just not labeled........... __________________ 1997 GMC Sierra Ext 1965 Mustang

09-01-2005, 01:07 PM	#7
sneakysnake It's a catastrophic success. Join Date: Jan 2003 Location: Oklahoma Posts: 2,077	You have your low beam stock wire energizing you high beam relays and vise versa. Nice schematic. Last edited by sneakysnake; 09-01-2005 at 01:10 PM.

09-01-2005, 02:01 PM	#8
68C15 blood type; Retumbo Join Date: Jan 2004 Location: next to my reloading bench Posts: 10,269	I see a couple of problems. the low bulbs in your diagram have the brown going to gnd. it should be fed power fromthe low relays. the green should feed both high & low bulbs. also one relay for high 7 another for low is sufficient. thats what I have on mine. using relays for the tail & brake-turn is a wasye of time & money. they dont draw enough current to warrant a relay. I agree though that the headlights being fed from a relay is a good idea. that way the light switch doesnt have to carry the load & there is more voltage at the bulbs. __________________ Man rule #77...if you own a 67 stepside with a caddy 472 you will never be in danger of loosing you man card

09-01-2005, 08:47 PM	#9
aquik72gmc350 Account Suspended Join Date: Aug 2005 Location: Ca Posts: 81	68c15 I'm kinda confused now. I marked each wire with a number. Can you tell me which ones are incorrect and what to change it to? Thank-you Attached Images

09-01-2005, 10:08 PM	#11
68C15 blood type; Retumbo Join Date: Jan 2004 Location: next to my reloading bench Posts: 10,269	Give Me A Few Minutes & I Will Try To Rework The Diagram For You __________________ Man rule #77...if you own a 67 stepside with a caddy 472 you will never be in danger of loosing you man card

08-31-2005, 05:48 PM	#1
aquik72gmc350 Account Suspended Join Date: Aug 2005 Location: Ca Posts: 81	I made GMC Headlite Diagram I made a GMC version of the headlite w/ relays. It uses 4 relays, 2 for headlites, and 2 for high beams. Next I'm working on doing my reverse lights, and brake/turn lights. Attached Images Last edited by aquik72gmc350; 09-01-2005 at 01:21 AM.

09-01-2005, 08:10 AM	#4
67chevemall Registered User Join Date: Apr 2003 Location: NB Posts: 3,367	That is one cool avatar^^^ How much more will it go? Government mobsters suck! force you to break the law. got weed? __________________ 1968 Chevy C10 307 3ott fleetside 1967 Chevy C/10 V8, 3spd, fleetside lwb.Sold 1967 Chev C/10 step, 383, M21. SOLD

09-01-2005, 08:55 AM	#5
sargentjones BOLT SMASHER Join Date: Jan 2005 Location: St.Catharines Posts: 51	who knows chief. a buck 13 a liter ain't high enough. Give er time bud, sh'll hit 2 in no time dime bags, dime bags.... get yer dime bags here::::::::::: __________________ Jeff 73 Chevy C-10 350 4-Speed RUST DON'T WAIT FOR NO ONE...... Last edited by sargentjones; 09-01-2005 at 08:59 AM.

09-01-2005, 09:43 PM	#10
sneakysnake It's a catastrophic success. Join Date: Jan 2003 Location: Oklahoma Posts: 2,077	OK, #5 stock wire should go to coil of the low beam relay and the #4 stock high should go to the coil of the high relay. Othe bulbs "68c15" mentioned are color coded wrong,the BROWN should be your power wire from the low relay and BLACK should be the ground. in other words #1 should be brown and chas grnd should be black. On a low beam light bulb you have three prongs one is ground one is low filament and the other is a high. A high beam bulb only has two prongs hot and ground So on your diagram you dont really need four relays,but if you insist.LOL then the two low relays should feed one prong on each low beam bulb. and the high relays should feed the high bulbs plus the other prong of the low beam bulbs. Hope that makes sense, your on the right track just need to tweek it a little

09-01-2005, 10:28 PM	#12
68C15 blood type; Retumbo Join Date: Jan 2004 Location: next to my reloading bench Posts: 10,269	I tried to re-do it on my computer with no luck. probably the best thing to do is call me after 8:30 Fri night (central time) & I will grab my diagram from work & walk you through it. look for a PM with my phone #. at this moment I dont remeber if the factory is green or tan for the low beams. PS, there is a way to do this with just one relay but it is somewhat complicated. __________________ Man rule #77...if you own a 67 stepside with a caddy 472 you will never be in danger of loosing you man card

09-01-2005, 11:43 PM	#13
sneakysnake It's a catastrophic success. Join Date: Jan 2003 Location: Oklahoma Posts: 2,077	heres a crude version to go by,dont laugh.LOL Attached Images

09-02-2005, 01:28 AM	#14
Project1970 14.1 @ 96MPH Join Date: Jul 2001 Location: Mesa, AZ Posts: 2,811	Yeah, also, there's no reason to need 4 relays. The brightest bulbs are what, 100W? 100W / 12V = about 8.3A per bulb. Those Bosch relays should be able to handle 30A with ease, and 16A should be no problem. __________________ Project1970 - LS1 Swap Complete!



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