Questions About Changing To Dual Headlights In 81 Model - The 1947 - Present Chevrolet & GMC Truck Message Board Network

wildmanaaron · 07-14-2006, 04:08 PM

I had some questions about changing over to Dual Headlights on a 1981 Model Blazer. I know this is the Truck board but (1) I figured more people would see it on this forum and (2) I figured that it would be the same from the Truck to the Blazer.

1. I know that the radiator supports are different between the single and dual lights models, but what is it that is different, just the places where the headlights go? I figured that there was some plates that had to be pryed off the tabs to access the hole for the wiring harness.

2. What re-wiring do you have to do? That´s the part that scares me a little! You can buy the pigtails to go into the new headlights, but I don´t know where to wire them up at.

Thanks guys!

Prerunner1982 · 07-14-2006, 04:44 PM

a chilton or haynes repair manual should have wiring diagram for headlight wiring. Might be worth the small investment atleast to have something to look at. Might also be worth it to find an 81-82 pickup with quad lights and pull the wiring harness off of it, if not to use completely, to pull wire from..

wildmanaaron · 07-14-2006, 04:49 PM

I have one somewhere but I dont think it has much. I just wonder if I would have any trouble with other things if I used a factory dual headlight front harness?

kevinr1970 · 07-14-2006, 05:33 PM

As far as I know, the core supports are different.
If you can find a donor/someone parting out a truck with the quad's, take the harness too. It's just some clips to the core support, fender and one bolt holding the fuse block to the firewall. Once the bolt comes out the block will split in half and you take the part that runs the front.
At least that was how it was on my '87. But I was going from '87 to '87 so you might want to find a similar year just in case.
***edit***
Since you have an '81 the harness will have different sockets for the turn signals for '83-87 trucks. But that would be an easy fix with cutting and splicing wires.

bigarmzz · 07-14-2006, 06:12 PM

the core supports are different

and the holes for the headlight adjusters are obviously different....if memory serves me right, the quad style has square headlight adjuster holes....(good luck trying to drill that small square hole)

moneyeater · 07-15-2006, 03:29 AM

This is what the ´81 coresupport looks like!
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I think it won´t be easy to get the propper opening in the support to fit the light in and be able to adjust it right!
I´m upgrading to the quadbeam setup but i´ll be fabricating the adjustment and holdingscrews to the headlampsurroundings!
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The wiring is the lighter part of that upgrade!My haynes manual served me well on that but now i added two relays to get the load from the lightswitch and more power to the lights!
There´s a wiringset to do that in the summitcatalog!

07-14-2006, 04:08 PM	#1
wildmanaaron Registered User Join Date: Mar 2002 Location: Bowling Green, KY Posts: 396	Questions About Changing To Dual Headlights In 81 Model I had some questions about changing over to Dual Headlights on a 1981 Model Blazer. I know this is the Truck board but (1) I figured more people would see it on this forum and (2) I figured that it would be the same from the Truck to the Blazer. 1. I know that the radiator supports are different between the single and dual lights models, but what is it that is different, just the places where the headlights go? I figured that there was some plates that had to be pryed off the tabs to access the hole for the wiring harness. 2. What re-wiring do you have to do? That´s the part that scares me a little! You can buy the pigtails to go into the new headlights, but I don´t know where to wire them up at. Thanks guys!

07-14-2006, 04:44 PM	#2
Prerunner1982 Registered User Join Date: Oct 2002 Location: Edmond, OK Posts: 5,906	Re: Questions About Changing To Dual Headlights In 81 Model a chilton or haynes repair manual should have wiring diagram for headlight wiring. Might be worth the small investment atleast to have something to look at. Might also be worth it to find an 81-82 pickup with quad lights and pull the wiring harness off of it, if not to use completely, to pull wire from.. __________________ Jon 1982 Chevy Silverado 350/th350.... RETIRED 1993 Jeep XJ 2 door(Cherokee) 4wd 4.0ltr/AX-15 (5spd)/NP231 .... Oklahoma Roll Call

07-14-2006, 04:49 PM	#3
wildmanaaron Registered User Join Date: Mar 2002 Location: Bowling Green, KY Posts: 396	Re: Questions About Changing To Dual Headlights In 81 Model I have one somewhere but I dont think it has much. I just wonder if I would have any trouble with other things if I used a factory dual headlight front harness?

07-14-2006, 05:33 PM	#4
kevinr1970 Senior Member Join Date: Aug 2004 Location: Everett, WA Posts: 2,316	Re: Questions About Changing To Dual Headlights In 81 Model As far as I know, the core supports are different. If you can find a donor/someone parting out a truck with the quad's, take the harness too. It's just some clips to the core support, fender and one bolt holding the fuse block to the firewall. Once the bolt comes out the block will split in half and you take the part that runs the front. At least that was how it was on my '87. But I was going from '87 to '87 so you might want to find a similar year just in case. *edit* Since you have an '81 the harness will have different sockets for the turn signals for '83-87 trucks. But that would be an easy fix with cutting and splicing wires. __________________ 2009 Honda Fit CfC (bsf 44.9 mpg) 2000 Tahoe Limited 1991 GMC CrewCab Dually 2wd, will end up swb, not dually and replace CCswb below 1991 GMC CrewCab Dually 4x4, just going to fix things up for now 1982/1989 K5/GMC Jimmy 2wd 1987 GMC 1/2 ton swb 2wd Crew (sold)

07-14-2006, 06:12 PM	#5
bigarmzz Registered User Join Date: Sep 2004 Location: Elkins, West Virginia Posts: 2,542	Re: Questions About Changing To Dual Headlights In 81 Model the core supports are different and the holes for the headlight adjusters are obviously different....if memory serves me right, the quad style has square headlight adjuster holes....(good luck trying to drill that small square hole) __________________ 1987 350 TBI lowered 5/7

07-15-2006, 03:29 AM	#6
moneyeater Registered User Join Date: Feb 2003 Location: Northern Germany,near Bremen Posts: 684	Re: Questions About Changing To Dual Headlights In 81 Model This is what the ´81 coresupport looks like! I think it won´t be easy to get the propper opening in the support to fit the light in and be able to adjust it right! I´m upgrading to the quadbeam setup but i´ll be fabricating the adjustment and holdingscrews to the headlampsurroundings! The wiring is the lighter part of that upgrade!My haynes manual served me well on that but now i added two relays to get the load from the lightswitch and more power to the lights! There´s a wiringset to do that in the summitcatalog!



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