Headlight Relay Mod

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MrMarty51

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First of all, I guess it would greatly help if a person understood what a relay is and how they work.
Here is a page, a simple tutorial for understanding the theory of how the automotive relay works and what each terminals job is. it is only one page with large letter writing and a few diagrams of how to wire the relay in most any application.
I would first read this before attempting to wire in Your own relay. Once the basics is understood it will take "ALL OF THE FRIGHT" out of wiring in Your own system.
One more thing, when tapping into a wire, through a splice, always stagger Your splices to keep from creating one great big knot of splices in one spot.
http://www.eurekaboy.com/f250/relay101.htm

Here is a pic. of the relay I installed on My 93. There is a lot of talk about diodes and such but just scroll down a bit and You`ll find the pics.
http://www.gmsquarebody.com/forum/showthread.php?t=5966&highlight=headlamp+diode
What I did was to tap into the bright headlamps wire, on the passenger side and then run a wire from the tap to where I was going to have My relay mounted, or hung.
Wire in the relay as prescribed and use the bright tapped in wire for the "Signal" wire, on the other side of the relay will be another wire run to ground.
Hook another wire into one of the battery terminal lugs and hook that, through a 20 amp fuse to the battery or + side of the relay, across the relay, from the + wire, hook that pigtail/terminal to another wire that You have run back to the headlamps wire harness and hook that wire into the "DIM" lights harness.
Now, when the headlamps are on dim, only the dim will light up.
When the headlamps are turned onto the "Bright" mode, a signal will be sent to the relay, through the switch incorporated in the relay to the ground turning the switch on.
When the switch is turned on, it will run power through the switch and back to the dim lamps bulbs turning them on while the bright lights is lit up.
If You have any questions, please post them up.
I hope this all helps and that You can/will wire in Your own system. That will be a very nice beginning, in the knowledge of automotive wiring for You.
 
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82chevy350

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Oh I have an idea already im in electrical II in college. id rather have a bunch of stuff have a relay which is why im thinking about converting to a newer fuse block system.
 

MrMarty51

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Oh I have an idea already im in electrical II in college. id rather have a bunch of stuff have a relay which is why im thinking about converting to a newer fuse block system.

And after finished will probably help to get more credits towards the degree too. :deal: LOL
 

Green79Scottsdale

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I am not very electrical smart, so it was easier for me to buy one. The one I got came with all the relay's and stuff that new vehicles utilize. There was no major re-working of the wiring system to a new fuse block system. All it does is use the old headlight on and off to switch the relay's to provide power.
 

da_raabi

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I have a printed copy of the schematic I got from an older truck (I think I got it on the 67-72 forums), I'll see if I can find and upload it.
 

MrMarty51

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:favorites13: here, have a beeer, :popcorn: some popcorn toooo.
 
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MrMarty51

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Some good stuff right there 8T
I saved that image to the desktop, stuffed it in My GM wiring folder.
Thank You very much.
 
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89Suburban

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Nice diagram
 

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