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73-87 Chevy _ GMC Trucks => 73-87 Chevy & GMC Trucks => Topic started by: 78 Chevyrado on December 14, 2010, 08:26:49 pm

Title: Headlight and Foglight Relays
Post by: 78 Chevyrado on December 14, 2010, 08:26:49 pm
Since I'm going to be wiring up my new fog lights, I might as well go ahead and put relays on the headlights too.  So I'll have 3 new relays under the hood.  Do you guys know of any ways to make this look as clean as possible?  I've been looking into Marine fuse blocks and such but I'm not having much luck.  I'd love to find something that is waterproof and will hold the 3 relays, fuses and a junction for one main power cable from 12V+ to run everything.  is there anything like this out there?  maybe a fuse panel out of a certain newer car or something?  A fuse block that will hold relays is what I want.

Any pics would be awesome.

I just want it as neat and OE-looking as possible.
Title: Re: Headlight and Foglight Relays
Post by: topp on December 14, 2010, 08:33:49 pm
Junk yard.

Some newer vehicles have relay blocks on the firewall
Title: Re: Headlight and Foglight Relays
Post by: VileZambonie on December 14, 2010, 08:47:17 pm
Any 1986 up GM mid size car will have what you want.

Here's an 87 buick lesabre
Title: Re: Headlight and Foglight Relays
Post by: 78 Chevyrado on December 15, 2010, 03:14:11 pm
I'm kinda thinking now I might get some more Hella Relays.  The one that came with the lights is blue and has a fuse slot built right into it.  I didn't know they had those.  I may do that as it would be pretty neat, without having to have 3 relay AND 3 fuse holders.  You guys know of any problems with that kind of relay?  I shouldn't think there would be.

Here's the Relay
(http://www.rallylights.com/images/87108_lg.jpg)

Here's the Lights
(http://i160.photobucket.com/albums/t195/wes2880/78%20C20%20-After%20New%20Wheels/DrivingLights1.jpg)
Title: Re: Headlight and Foglight Relays
Post by: jaredts on December 15, 2010, 06:45:16 pm
I've never seen such a thing, but that's a cool idea.  It should be safe as long as the headlights don't draw more amps than the relay/fuse can handle.
Title: Re: Headlight and Foglight Relays
Post by: 78 Chevyrado on December 15, 2010, 06:48:02 pm
^^  good thinking.   So what AMP relay should I use for the headlights?  Assume a super bright 9003 bulb.  As I may buy those jeep headlights, or either the DOT 7" Hellas.  I'm liking the Hellas more and more though.  Do the high beams draw higher amps than the low beams?
Title: Re: Headlight and Foglight Relays
Post by: topp on December 15, 2010, 07:51:14 pm
Some formulas....

http://www.powerstream.com/Amps-Watts.htm

Do it for 1 light, and then multiply by all the lights on the circuit (should only be 2 per circuit) and then double....
Title: Re: Headlight and Foglight Relays
Post by: 78 Chevyrado on December 15, 2010, 08:01:46 pm
So I'll call it 10A for a pair of 55W bulbs.  I'll find me 2 more hella relays like came with the fog lights and call it a day.

Good deal, Thanks topp!
Title: Re: Headlight and Foglight Relays
Post by: topp on December 15, 2010, 09:33:02 pm
Your gonna draw about 5 amps a light...
X2 lights= about 10 amps...
So 20 should do it for your fuse.
Title: Re: Headlight and Foglight Relays
Post by: VileZambonie on December 15, 2010, 09:37:45 pm
5 Amps

volts x amps = watts

And topp is correct. Just remember to wire the relay to the lights on the load side.
Title: Re: Headlight and Foglight Relays
Post by: 78 Chevyrado on December 16, 2010, 06:53:12 am
Thanks guys, I'm gonna get the 25A Relays and I'll put a 20A Fuses in them.
Title: Re: Headlight and Foglight Relays
Post by: 78 Chevyrado on December 20, 2010, 05:59:29 pm
Got the lights wired up today.   I forgot how much brighter those are than the headlights.  They look half again brighter and They send light at least twice as far.

I like em, I like em a lot.

I wired them in on the high beams so I can aim them to actually do some good.  We have LOTS of deer round here.  They're so much brighter than the silverstar sealed beams I have.  I'll be doing relays for them before too much longer I think.

Used as much of the stock wiring loom as I could, these two short runs of loom to the relay are the only visible additions.
(http://i160.photobucket.com/albums/t195/wes2880/78%20C20%20-After%20New%20Wheels/Hella550DrivingLightsRelay.jpg)

Onto the good stuff, and right now they're aimed a little too low.  I haven't tried them on the road, only have an initial aiming done.
(http://i160.photobucket.com/albums/t195/wes2880/78%20C20%20-After%20New%20Wheels/Hella550DrivingLights2.jpg)
(http://i160.photobucket.com/albums/t195/wes2880/78%20C20%20-After%20New%20Wheels/Hella550DrivingLights.jpg)
Title: Re: Headlight and Foglight Relays
Post by: Grim 82 on December 20, 2010, 06:15:42 pm
That's cool. Did you get the relays directly from Hella? I'd like to do something similar on my truck.
Title: Re: Headlight and Foglight Relays
Post by: 78 Chevyrado on December 20, 2010, 06:30:05 pm
That's cool. Did you get the relays directly from Hella? I'd like to do something similar on my truck.

Yeah the relay came in the kit.  It was complete.  the only thing I needed that wasn't in the kit was the wire loom stuff.