Headlight relay install You Gatta do it. - Page 6 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Russell · 10-22-2005, 11:27 AM

Quote:

Originally Posted by KEH

Percentage of full light output at various voltages, with 12.6 volts being "100%" :

12.6v = 100%
11.5v = 75%
10.3v = 50%
8.7v = 25%

This is all very true, but remember that your truck operates at 14.9 - 15 volts with a properly operating alternator. So, you'd actually wind up getting about 11.3 volts at the headlights, using the same ratio of 9.5 volts at the lights when operating at 12.5 volts.

So, that number puts you at about 75% lighting -- Using a relay install, you drop your losses to about .4 volts or so, according to your information. That means that with a relay harness, and a properly operating alternator, you could very well be getting over 14 volts straight to your headlights. Thats why this makes such a phenominal difference in lighting. Its like overclocking your lights!

**special-K** · 10-22-2005, 01:22 PM

Quote:

Originally Posted by grendel

The new harness uses the old one as a switched power source.

If you have a problem with the old circuit, you'll probably have a problem with the new one.

I was thinking maybe for now run this relay harness directly to the switch and abandoning the wiring on the out side of the switch.No can do?

*FormerMember* · 10-22-2005, 04:44 PM

Quote:

Originally Posted by special-K

I was thinking maybe for now run this relay harness directly to the switch and abandoning the wiring on the out side of the switch.No can do?

You can do that. Would take a bit of work, but not too tough.

**special-K** · 10-23-2005, 07:06 AM

Kewwwlll.

*FormerMember* · 10-23-2005, 08:24 AM

You have to cut the harness you're buying and extend the activation wire in to your cab.

76bonanza · 10-23-2005, 11:40 AM

how can you tell if PO has done this already? Lots of new wiring in truck.
Also how much more wiring under the hood can be seen and is it all under hood work or some in cab work? Thanks.

Bill72BB · 10-23-2005, 11:52 AM

Quote:

Originally Posted by special-K

Kewwwlll.

This is a great mod ,

B4 I did it I would make sure the Headlight switch isn't the problem .

Striker169 · 10-23-2005, 02:00 PM

Quote:

Originally Posted by 76bonanza

how can you tell if PO has done this already? Lots of new wiring in truck.
Also how much more wiring under the hood can be seen and is it all under hood work or some in cab work? Thanks.

You have to look for some relays which are little black boxes that have 4 wires running out of it. Earlier in this post someone posted a picture of 4 of them in a row

76bonanza · 10-23-2005, 03:36 PM

were at?

O'skool 72GMC · 10-23-2005, 08:11 PM

I want to do it, but i need to be taken by the hand here!!!
I want to replace my sealed beams with the Hella's
I have a GMC. I have a copy of the wiring schematic.
Where do i put the 30a inline fuse ?
Can i still use my original headlight switch?

Anyone???? Beuller????

Russell · 10-23-2005, 08:55 PM

Very easy to do

For the wiring, the 30 amp fuse goes between the relay's pin number 30, and the battery. Pin 87 goes to your light. Pin 85 goes to ground, and Pin 86 goes to your original wiring from the headlight highbeam switch on the floor.

4x4Poet · 10-23-2005, 08:56 PM

Quote:

Originally Posted by O'skool 72GMC

I want to do it, but i need to be taken by the hand here!!!
I want to replace my sealed beams with the Hella's
I have a GMC. I have a copy of the wiring schematic.
Where do i put the 30a inline fuse ?
Can i still use my original headlight switch?...

Yes, changing to headlight relays retains the original headlight switch. All the wiring changes are done under the hood. IIRC, the 30A inline fuse goes on the power wire between the power source (alternator) and the relays.

Someone posted a headlight relay wiring diagram earlier in the thread. I also posted these links earlier:
http://www.madelectrical.com/electri...adlights.shtml
http://www.madelectrical.com/electri...dlights2.shtml

*wolfthing2000* · 11-27-2005, 03:57 PM

If it helps anyone out, I spent about an hour with the Napa counter and they finaly found these: Napa Part 192D , Lighting by Trucklite
12V 40 Amp/ they cost 8.49 each

they wire up: 30 battery, 87 or 87a lights, 85 ground and 86 from dimmer switch.

seem to be good quality (import) for the price.

I was told that Bosch are 3 xs the price, of course higher quality.

willow72 · 11-29-2005, 06:45 PM

yall need too check out partsexpress.com bosch relays that i got from them for my truck were only 1.99 each they have everything you need i already installed mine and they work great took about three days for delivery check them out partsexspress.com they have the 40amp ones for 1.79 but they arnt bosch they also have water proof 40 amp ones for 2.50 each http://partsexpress.com

vtblazer · 11-29-2005, 08:09 PM

Seeing alot of 30 & 40 amp stuff mentioned here.

Hope everyone remembers to run the appropriate size fuse and wire size when doing all this up-grading.

Fused @ 10amps needs 16 guage wire
Fused @ 15amps needs 14 guage wire
Fused @ 20amps needs 12 guage wire
Fused @ 30amps needs 10 guage wire
Fused @ 40amps needs 8 guage wire

matt67350 · 11-29-2005, 08:42 PM

I'll do a FAQ with pic's and info if it will help.
The install is easy. Some guy's are upgrading or changing to a different headlight. That will cost more, but to just install the relays you should be able to get out cheap. $10.00 or less.

Matthew

Bill72BB · 11-29-2005, 09:04 PM

Good Info. vtblazer
If I remember right 55/65 watt bulbs will draw about 11 amps
and 85/100 watt bulbs will draw about 17 amps .

Quote:

Originally Posted by vtblazer

Seeing alot of 30 & 40 amp stuff mentioned here.

Hope everyone remembers to run the appropriate size fuse and wire size when doing all this up-grading.

Fused @ 10amps needs 16 guage wire
Fused @ 15amps needs 14 guage wire
Fused @ 20amps needs 12 guage wire
Fused @ 30amps needs 10 guage wire
Fused @ 40amps needs 8 guage wire

454_72_4X4 · 11-29-2005, 11:12 PM

What gauge wires does the Summit AMC-509102 kit use?

Couple more questions.
Since this kit is an APC product, shouldn't I be able to get it locally at Autozone or someplace that sells APC products?

Anybody got a website for APC?

Bill72BB · 11-30-2005, 10:57 AM

It's been a month or so since I installed the kit ,but from what I remember it's 12 gauge wire and will work with the 100 watt bulbs .I threw out all the paper work so I hope someone else can verify this .

Quote:

Originally Posted by 454_72_4X4

What gauge wires does the Summit AMC-509102 kit use?

Couple more questions.
Since this kit is an APC product, shouldn't I be able to get it locally at Autozone or someplace that sells APC products?

Anybody got a website for APC?

davidh · 11-30-2005, 12:14 PM

Lots of good info here.

stueber68 · 11-30-2005, 02:44 PM

With all of this setup does the indicator on the dash still work properly?

Brad · 11-30-2005, 05:13 PM

Yes- does not change it at all.

Quote:

Originally Posted by stueber68

With all of this setup does the indicator on the dash still work properly?

69TowRig · 11-30-2005, 11:32 PM

I just checked the voltage at the bulbs for my stock system.

At 14.7ish Volts at the battery, I get 13.05V at the driver's headlight and 12.62V at the passenger headlight. I don't know if it would be worth my trouble to upgrade it. What do y'all think?

*FormerMember* · 11-30-2005, 11:40 PM

Quote:

Originally Posted by 69TowRig

I just checked the voltage at the bulbs for my stock system.

At 14.7ish Volts at the battery, I get 13.05V at the driver's headlight and 12.62V at the passenger headlight. I don't know if it would be worth my trouble to upgrade it. What do y'all think?

I would say that it is.

Yes, you can buy the APC kits at Autozone. It's where i bought my first one 3 years ago for my C20. It's also why I posted this here. One of the best mods you can do. Even if Kurt had to post the right one for this application

kbs71 · 12-01-2005, 04:23 AM

There are several places to get good quality electrical parts and hardware. The terminals for the headlights are 5/16" and are available at Ron Francis
http://www.parts123.com/parts123/yb....rta~partsort~2 P/N AM-8 you get 8 for $7.95. Or you can get 50 if you think you need that many. This way you can just buy bulk wire and make your own harness. The other ends are 1/4" and can be had at MAD Electric http://www.madelectrical.com/catalog/flat-blade.shtml P/N 10-56F10 you get 10 for $2.99 or again 50 if need be. You can either buy their fancy wire or just go to your local Auto zone or NAPA and pick up some bulk wire. You'll need Brown, Green and Red and some Black. Then just make up your own harness. Relays, I really likes the ones at Parts Express http://www.partsexpress.com/pe/showd...number=339-075 P/N 339075 for the socket and 330-077 for the relays you'll nedd 2 of each. The H4 Lens can be had a JC Witless http://www.jcwhitney.com/autoparts/I...D:100000165791 P/N ZX139317U $17.99 They also have replacement bulbs all diffrent wattages.

10-23-2005, 07:06 AM	#129
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,863	Re: Headlight relay install You Gatta do it. Kewwwlll. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

10-23-2005, 08:24 AM	#130
FormerMember Account Suspended Join Date: Feb 2004 Posts: 3,051	Re: Headlight relay install You Gatta do it. You have to cut the harness you're buying and extend the activation wire in to your cab.

10-23-2005, 11:40 AM	#131
76bonanza Senior Member Join Date: Mar 2003 Location: St robert Mo Posts: 2,001	Re: Headlight relay install You Gatta do it. how can you tell if PO has done this already? Lots of new wiring in truck. Also how much more wiring under the hood can be seen and is it all under hood work or some in cab work? Thanks. __________________ 1968 c10 lowered 3" 4" 355/Th400 built by Hatfield racing in joplin MO

10-23-2005, 03:36 PM	#134
76bonanza Senior Member Join Date: Mar 2003 Location: St robert Mo Posts: 2,001	Re: Headlight relay install You Gatta do it. were at? __________________ 1968 c10 lowered 3" 4" 355/Th400 built by Hatfield racing in joplin MO

10-23-2005, 08:11 PM	#135
O'skool 72GMC Registered User Join Date: Jan 2002 Location: San Diego, CA, USA Posts: 251	Re: Headlight relay install You Gatta do it. I want to do it, but i need to be taken by the hand here!!! I want to replace my sealed beams with the Hella's I have a GMC. I have a copy of the wiring schematic. Where do i put the 30a inline fuse ? Can i still use my original headlight switch? Anyone???? Beuller????

10-23-2005, 08:55 PM	#136
Russell Professional Grade Join Date: May 2003 Location: Fort McMurray, Alberta Posts: 7,915	Re: Headlight relay install You Gatta do it. Very easy to do For the wiring, the 30 amp fuse goes between the relay's pin number 30, and the battery. Pin 87 goes to your light. Pin 85 goes to ground, and Pin 86 goes to your original wiring from the headlight highbeam switch on the floor. __________________ 1995 Chevrolet 2 Door Tahoe (6.6L LBZ Duramax / ZF6 / NP241 with 1 ton solid axle swap)

11-27-2005, 03:57 PM	#138
wolfthing2000 Account Suspended Join Date: Oct 2004 Posts: 1,276	Re: Headlight relay install You Gatta do it. If it helps anyone out, I spent about an hour with the Napa counter and they finaly found these: Napa Part 192D , Lighting by Trucklite 12V 40 Amp/ they cost 8.49 each they wire up: 30 battery, 87 or 87a lights, 85 ground and 86 from dimmer switch. seem to be good quality (import) for the price. I was told that Bosch are 3 xs the price, of course higher quality.

11-29-2005, 06:45 PM	#139
willow72 Registered User Join Date: Nov 2003 Location: dallas/ftwoth Posts: 112	Re: Headlight relay install You Gatta do it. yall need too check out partsexpress.com bosch relays that i got from them for my truck were only 1.99 each they have everything you need i already installed mine and they work great took about three days for delivery check them out partsexspress.com they have the 40amp ones for 1.79 but they arnt bosch they also have water proof 40 amp ones for 2.50 each http://partsexpress.com

11-29-2005, 08:09 PM	#140
vtblazer Registered User Join Date: Oct 2003 Location: Central Vermont Posts: 8,538	Re: Headlight relay install You Gatta do it. Seeing alot of 30 & 40 amp stuff mentioned here. Hope everyone remembers to run the appropriate size fuse and wire size when doing all this up-grading. Fused @ 10amps needs 16 guage wire Fused @ 15amps needs 14 guage wire Fused @ 20amps needs 12 guage wire Fused @ 30amps needs 10 guage wire Fused @ 40amps needs 8 guage wire

11-29-2005, 08:42 PM	#141
matt67350 Registered User Join Date: May 2001 Location: Benbrook, TX Posts: 1,060	Re: Headlight relay install You Gatta do it. I'll do a FAQ with pic's and info if it will help. The install is easy. Some guy's are upgrading or changing to a different headlight. That will cost more, but to just install the relays you should be able to get out cheap. $10.00 or less. Matthew __________________ 69 swb stepside, rebuild and upgrade in progress

11-29-2005, 11:12 PM	#143
454_72_4X4 Registered User Join Date: Apr 2004 Location: N.E. MO Posts: 1,749	Re: Headlight relay install You Gatta do it. What gauge wires does the Summit AMC-509102 kit use? Couple more questions. Since this kit is an APC product, shouldn't I be able to get it locally at Autozone or someplace that sells APC products? Anybody got a website for APC? __________________ 72 C20 4X4 454 4 speed 89 Trans Am (was) 305 TPI 700r4 93 C1500 2wd Extended cab 350 700r4 98 Sonoma (TPI outa the Trans Am) 03 Yamaha 660 Raptor 03/04 660 Raptor 07 700 Raptor 85 Honda Odyssey Last edited by 454_72_4X4; 11-29-2005 at 11:19 PM.

11-30-2005, 12:14 PM	#145
davidh Senior Member Join Date: Feb 2004 Location: Ponca city now kingfisher Oklahoma Posts: 1,221	Re: Headlight relay install You Gatta do it. Lots of good info here.

11-30-2005, 02:44 PM	#146
stueber68 1968 C20 Vortec Beast Join Date: Jun 2005 Location: STILLWATER,OKLAHOMA Posts: 483	Re: Headlight relay install You Gatta do it. With all of this setup does the indicator on the dash still work properly? __________________ Ugly or not it still kicks a**!

11-30-2005, 11:32 PM	#148
69TowRig Senior Member Join Date: Jan 2005 Location: Raleigh, NC Posts: 894	Re: Headlight relay install You Gatta do it. I just checked the voltage at the bulbs for my stock system. At 14.7ish Volts at the battery, I get 13.05V at the driver's headlight and 12.62V at the passenger headlight. I don't know if it would be worth my trouble to upgrade it. What do y'all think? __________________ -Chris Building a stripper, one part at a time: 1969 K5, 307, 3spd, 3 seats, hard top. Added Pwr Discs, Pwr Steering, Aux Battery, T-case Skid, Lighted Sidemarkers, HEI, Lock-Right Diff, ECE Class IV Hitch, 32" MT/Rs. Parts to Install: Hand Throttle, Console, Tow Hooks, Dual Horns, AM-FM, Dealer Swing-Away Tire Carrier, Gas Tank Skid. Also building a 1950 Willys CJ-3A and off-roading a 2001 Nissan Frontier on 1-Ton Portals...

12-01-2005, 04:23 AM	#150
kbs71 71 rustless in texas Join Date: Aug 2004 Location: Houston, TX Posts: 257	Re: Headlight relay install You Gatta do it. There are several places to get good quality electrical parts and hardware. The terminals for the headlights are 5/16" and are available at Ron Francis http://www.parts123.com/parts123/yb....rta~partsort~2 P/N AM-8 you get 8 for $7.95. Or you can get 50 if you think you need that many. This way you can just buy bulk wire and make your own harness. The other ends are 1/4" and can be had at MAD Electric http://www.madelectrical.com/catalog/flat-blade.shtml P/N 10-56F10 you get 10 for $2.99 or again 50 if need be. You can either buy their fancy wire or just go to your local Auto zone or NAPA and pick up some bulk wire. You'll need Brown, Green and Red and some Black. Then just make up your own harness. Relays, I really likes the ones at Parts Express http://www.partsexpress.com/pe/showd...number=339-075 P/N 339075 for the socket and 330-077 for the relays you'll nedd 2 of each. The H4 Lens can be had a JC Witless http://www.jcwhitney.com/autoparts/I...D:100000165791 P/N ZX139317U $17.99 They also have replacement bulbs all diffrent wattages. __________________ "The secret to creativity is knowing how to hide your sources." "No one really listens to anyone else, and if you try it for a while you'll see why" 71 C-10 LWB presently in a perpetual state of disassembly '96 Toyota (my work car) '04 Mustang Convertable (wife's car & other money pit) Latest aquesition and why my trucks still in the garage covered with junk.. 2010 Aqua Blue metallic 6 speed Manual LS3 2SS/RS Camaro (I want one of these in my truck FAQ here VENDORS here SUPPORT THE BOARD here My second favorite SITE



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