how to incorporate addictional running lights properly? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

jumpsoffrock · 06-15-2014, 10:09 PM

Where in the harness would I incorporate additional running lights on the bed? These lights have been there forever, but the way they were wired in is non-existent and I would like to not only re-do it, but do it the way a professional shop or factory would.

The rear wiring harness in my truck is butchered, and to add insult to injury, the mess that's left behind looks like it has been torn to shreds and is hanging from every corner...

...in other words nothing is hooked up and nothing works.(in the rear of the truck).

Which circuit would I add running lights without overburdening any circuit?

http://www.chrismeadtattoos.com/wiring/harness_back.jpg

63 & 64 Bowties · 06-16-2014, 07:59 AM

I would use a relay. Any existing headlight switch wire can be used for the trip-wire on the relay. Only takes low draw to trip a relay. Wire directly from the battery with inline fuse for the power to the lights. That way you can put unlimited number (up to the relay's rating) of lights on the circuit without overheating the headlight switch.
Here's a complete kit:
http://www.ebay.com/itm/New-HID-LED-..._Tools&vxp=mtr
Throw away that switch in the kit and instead tap into a hot-when-on wire on your headlight switch.

jumpsoffrock · 06-16-2014, 08:34 PM

Thank you very much for the help. Once I get the rest of the rear wiring in order, this is what I'll probably do.

willett · 06-19-2014, 03:01 PM

Buy a roll of 4 wire round trailer harness. Run it from up front to a trailer junction box in the back. Split off from there. That's how I would do it any ways.

mrolds88 · 06-19-2014, 03:19 PM

I would pull all the old junk off of the truck. Keep the pigtail from the harness and rebuild from scratch. You really only need 3 wire trailer wire as the white is ground. As far as the marker lights, unless you are planning to have a rolling Christmas tree, you shouldn't need any special extra wiring. If you are worried about amp draw, use LEDs. They draw about nothing. Also most marker lights use a 194 type bulb, so a trip through Ebay would hook you up. Just make sure you have a good ground cable from the bed to the frame. And solder and shrink wrap is your friend!!!!

willett · 06-19-2014, 04:37 PM

The extra wire is helpful if you ever need power back there for something else

jumpsoffrock · 06-19-2014, 07:23 PM

I'm currently trying to cover the whole harness to find any problems and fix them, and to organize the mess that I found. Thank you all very much, and I will most likely run something to the rear since I will most likely put a spotlight back there at some point. Additionally, if I ever switch to an electric cooling fan--necessitating a higher amp alternator--I will then probably run some regular house-type receptacles as well.

This trucks electrical upgrades are far from over.
Thanks again.

06-15-2014, 10:09 PM	#1
jumpsoffrock Registered User Join Date: Apr 2014 Location: California Posts: 976	how to incorporate addictional running lights properly? Where in the harness would I incorporate additional running lights on the bed? These lights have been there forever, but the way they were wired in is non-existent and I would like to not only re-do it, but do it the way a professional shop or factory would. The rear wiring harness in my truck is butchered, and to add insult to injury, the mess that's left behind looks like it has been torn to shreds and is hanging from every corner... ...in other words nothing is hooked up and nothing works.(in the rear of the truck). Which circuit would I add running lights without overburdening any circuit? http://www.chrismeadtattoos.com/wiring/harness_back.jpg

06-16-2014, 07:59 AM	#2
63 & 64 Bowties and a few others Join Date: Jun 2007 Location: Blue Ridge Mountains of VA Posts: 5,638	Re: how to incorporate addictional running lights properly? I would use a relay. Any existing headlight switch wire can be used for the trip-wire on the relay. Only takes low draw to trip a relay. Wire directly from the battery with inline fuse for the power to the lights. That way you can put unlimited number (up to the relay's rating) of lights on the circuit without overheating the headlight switch. Here's a complete kit: http://www.ebay.com/itm/New-HID-LED-..._Tools&vxp=mtr Throw away that switch in the kit and instead tap into a hot-when-on wire on your headlight switch. __________________ Bill US Army Vet -193rd Infantry BlueRidgeMuscleCars.com “The greatness of a nation and its moral progress can be judged by the way its animals are treated” Gandhi

06-16-2014, 08:34 PM	#3
jumpsoffrock Registered User Join Date: Apr 2014 Location: California Posts: 976	Re: how to incorporate addictional running lights properly? Thank you very much for the help. Once I get the rest of the rear wiring in order, this is what I'll probably do.

06-19-2014, 03:01 PM	#4
willett Another Day, Another Dollar Join Date: Nov 2008 Location: North Vancouver, BC Posts: 1,316	Re: how to incorporate addictional running lights properly? Buy a roll of 4 wire round trailer harness. Run it from up front to a trailer junction box in the back. Split off from there. That's how I would do it any ways. __________________ -78 K20 Cheyenne 454 long box, 4" lift, 35" MT's, '84 cab, '80 box "its hip to be square"

06-19-2014, 03:19 PM	#5
mrolds88 Registered User Join Date: Jul 2011 Location: WV Posts: 946	Re: how to incorporate addictional running lights properly? I would pull all the old junk off of the truck. Keep the pigtail from the harness and rebuild from scratch. You really only need 3 wire trailer wire as the white is ground. As far as the marker lights, unless you are planning to have a rolling Christmas tree, you shouldn't need any special extra wiring. If you are worried about amp draw, use LEDs. They draw about nothing. Also most marker lights use a 194 type bulb, so a trip through Ebay would hook you up. Just make sure you have a good ground cable from the bed to the frame. And solder and shrink wrap is your friend!!!! __________________ 72 GMC C2500 402/Th400 first truck (still have) 77 GMC C3500 CC dually Sold 70 C50 dump truck "Rusty" 87 K10 Suburban Sold 93 K2500 xcab 6.5TD 96 GMC K2500 Suburban 6.5 TD

06-19-2014, 04:37 PM	#6
willett Another Day, Another Dollar Join Date: Nov 2008 Location: North Vancouver, BC Posts: 1,316	Re: how to incorporate addictional running lights properly? The extra wire is helpful if you ever need power back there for something else __________________ -78 K20 Cheyenne 454 long box, 4" lift, 35" MT's, '84 cab, '80 box "its hip to be square"

06-19-2014, 07:23 PM	#7
jumpsoffrock Registered User Join Date: Apr 2014 Location: California Posts: 976	Re: how to incorporate addictional running lights properly? I'm currently trying to cover the whole harness to find any problems and fix them, and to organize the mess that I found. Thank you all very much, and I will most likely run something to the rear since I will most likely put a spotlight back there at some point. Additionally, if I ever switch to an electric cooling fan--necessitating a higher amp alternator--I will then probably run some regular house-type receptacles as well. This trucks electrical upgrades are far from over. Thanks again.



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