cut hole in firewall for Painless Wiring Harness? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

FLcustom10 · 06-04-2011, 05:58 PM

It looks like I'm going to have to cut the hole in the firewall bigger for the Painless Wiring Harness. From about 2 1/4 " square to 2 1/2 " square?
Does anyone have instructions / advice on the best way to do this?

Thank you,

Tom

68gmsee · 06-04-2011, 06:19 PM

Are you sure?

I don't have an answer but I thought "Painless" meant you didn't have to do any major surgery. I was looking to replace the wiring on my 69 but now I'm going to have to take another look. I sure don't want to have to do any sheet metal cutting.

jackyl9999 · 06-04-2011, 06:24 PM

You have to enlarge the factory hole I believe. It was not that big of a deal.
I masked it off and used a grinder w/ a cut off wheel.

**Daddy Brim** · 06-04-2011, 07:23 PM

I made copies of the templet in the back of the instructions for the hole tape in place mark with a scribe , then use a die grinder with grinding wheel to open it up. Start checking whin you get close .

DesertCat · 06-04-2011, 07:30 PM

You'll need a 2.5" square firewall hole saw... very hard to find.

FLcustom10 · 06-04-2011, 11:43 PM

LOL Desertcat - I've been looking for that square hole saw for a while now. Thanks guys. I'll give it a try tomorrow.

Sillyoldman · 06-04-2011, 11:54 PM

Quote:

Originally Posted by DesertCat

You'll need a 2.5" square firewall hole saw... very hard to find.

I used my Blockbit to cut mine. A little spendy but worth it 10 times over.

lil hoodlum · 06-05-2011, 09:34 AM

I also have a painless wire harness. I used a Dremmel with a cut off wheel. It really wasn't a big deal. Took me around 20 minutes. The best part about re-wiring the truck is no more funny little electrical gremlins anymore. I installed mine at least 7 years ago and have not had a single problem since. I knew it was time to re-wire when my headlights and dash lights started flickering. It probably would be bad to lose the headlights while driving at night.

Good luck!

Keith

68gmsee · 06-05-2011, 10:36 AM

Quote:

Originally Posted by Sillyoldman

I used my Blockbit to cut mine. A little spendy but worth it 10 times over.

What's a blockbit?

**VetteVet** · 06-05-2011, 11:28 AM

Here's the painless manual and the template is on the last page. There is tons of great information here but beware some of it is for fords and mopars.

http://www.painlessperformance.com/Manuals/10104.pdf

FLcustom10 · 06-05-2011, 07:35 PM

Thanks guys. I wound up using a dremel tool. It wasn't bad at all. Here's some pictures.

FLcustom10 · 06-05-2011, 07:39 PM

A few more pictures.

bruceman1968 · 06-05-2011, 07:55 PM

Looks good FLcustom10, Are you gonna start a build thread?

FLcustom10 · 06-05-2011, 08:12 PM

Thanks Bruceman. It looks like I do need to start a build thread. I'll try to get it going soon.

Tom

bruceman1968 · 06-05-2011, 08:19 PM

I will be a subscriber, that looks like a great project you got goin there. And a nice color of Blue.

Steve Van Gent · 06-06-2011, 10:18 PM

You guys ever consider using Isis?

http://www.isispower.com/products.ht...ctID=ISIS3BOXZ

**Daddy Brim** · 06-06-2011, 10:31 PM

That is just how I did mine. Now just take your time when routing your wires to make the harness.

Ackattack · 06-06-2011, 11:29 PM

a body saw would do it real easy

FLcustom10 · 06-07-2011, 06:36 PM

Thanks guys. Bruce here's my build thread. I'll just have to add to it a little at a time. I look forward to reading yours too.

http://67-72chevytrucks.com/vboard/s...d.php?t=468335

06-04-2011, 05:58 PM	#1
FLcustom10 Registered User Join Date: Feb 2007 Location: Tallahassee, FL Posts: 322	cut hole in firewall for Painless Wiring Harness? It looks like I'm going to have to cut the hole in the firewall bigger for the Painless Wiring Harness. From about 2 1/4 " square to 2 1/2 " square? Does anyone have instructions / advice on the best way to do this? Thank you, Tom

06-04-2011, 06:19 PM	#2
68gmsee Active Member Join Date: Jul 2007 Location: Centrally located between Houston, Austin and Waco. BCS area. Posts: 7,947	Re: cut hole in firewall for Painless Wiring Harness? Are you sure? I don't have an answer but I thought "Painless" meant you didn't have to do any major surgery. I was looking to replace the wiring on my 69 but now I'm going to have to take another look. I sure don't want to have to do any sheet metal cutting.

06-04-2011, 06:24 PM	#3
jackyl9999 Registered User Join Date: Feb 2003 Location: Paragould, Ar Posts: 571	Re: cut hole in firewall for Painless Wiring Harness? You have to enlarge the factory hole I believe. It was not that big of a deal. I masked it off and used a grinder w/ a cut off wheel. __________________ 1970 Gmc Grande Sierra Swb 2wd LSX (LQ4/4L80e) 1990 K1500 Daily

06-04-2011, 07:23 PM	#4
Daddy Brim Senior Member Join Date: Feb 2011 Location: Clovis Ca. Posts: 632	Re: cut hole in firewall for Painless Wiring Harness? I made copies of the templet in the back of the instructions for the hole tape in place mark with a scribe , then use a die grinder with grinding wheel to open it up. Start checking whin you get close .

06-04-2011, 07:30 PM	#5
DesertCat Registered User Join Date: Mar 2011 Location: Valley of the Sunstroke, Arizona Posts: 1,210	Re: cut hole in firewall for Painless Wiring Harness? You'll need a 2.5" square firewall hole saw... very hard to find. __________________ My build thread - Devastation and Reform http://67-72chevytrucks.com/vboard/s...d.php?t=567131

06-04-2011, 11:43 PM	#6
FLcustom10 Registered User Join Date: Feb 2007 Location: Tallahassee, FL Posts: 322	Re: cut hole in firewall for Painless Wiring Harness? LOL Desertcat - I've been looking for that square hole saw for a while now. Thanks guys. I'll give it a try tomorrow.

06-05-2011, 09:34 AM	#8
lil hoodlum Registered User Join Date: Oct 2009 Location: Denton, Texas Posts: 1,735	Re: cut hole in firewall for Painless Wiring Harness? I also have a painless wire harness. I used a Dremmel with a cut off wheel. It really wasn't a big deal. Took me around 20 minutes. The best part about re-wiring the truck is no more funny little electrical gremlins anymore. I installed mine at least 7 years ago and have not had a single problem since. I knew it was time to re-wire when my headlights and dash lights started flickering. It probably would be bad to lose the headlights while driving at night. Good luck! Keith

06-05-2011, 11:28 AM	#10
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,718	Re: cut hole in firewall for Painless Wiring Harness? Here's the painless manual and the template is on the last page. There is tons of great information here but beware some of it is for fords and mopars. http://www.painlessperformance.com/Manuals/10104.pdf __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative.

06-05-2011, 07:35 PM	#11
FLcustom10 Registered User Join Date: Feb 2007 Location: Tallahassee, FL Posts: 322	Re: cut hole in firewall for Painless Wiring Harness? Thanks guys. I wound up using a dremel tool. It wasn't bad at all. Here's some pictures. Attached Images

06-05-2011, 07:39 PM	#12
FLcustom10 Registered User Join Date: Feb 2007 Location: Tallahassee, FL Posts: 322	Re: cut hole in firewall for Painless Wiring Harness? A few more pictures. Attached Images

06-05-2011, 07:55 PM	#13
bruceman1968 Registered User Join Date: Oct 2009 Location: Tampa Bay Posts: 1,549	Re: cut hole in firewall for Painless Wiring Harness? Looks good FLcustom10, Are you gonna start a build thread? __________________ CHEVY/GMC VIN DECODERS

06-05-2011, 08:12 PM	#14
FLcustom10 Registered User Join Date: Feb 2007 Location: Tallahassee, FL Posts: 322	Re: cut hole in firewall for Painless Wiring Harness? Thanks Bruceman. It looks like I do need to start a build thread. I'll try to get it going soon. Tom Last edited by FLcustom10; 06-05-2011 at 08:12 PM.

06-05-2011, 08:19 PM	#15
bruceman1968 Registered User Join Date: Oct 2009 Location: Tampa Bay Posts: 1,549	Re: cut hole in firewall for Painless Wiring Harness? I will be a subscriber, that looks like a great project you got goin there. And a nice color of Blue. __________________ CHEVY/GMC VIN DECODERS

06-06-2011, 10:18 PM	#16
Steve Van Gent Registered User Join Date: Feb 2009 Location: Redding, Ca Posts: 333	Re: cut hole in firewall for Painless Wiring Harness? You guys ever consider using Isis? http://www.isispower.com/products.ht...ctID=ISIS3BOXZ

06-06-2011, 10:31 PM	#17
Daddy Brim Senior Member Join Date: Feb 2011 Location: Clovis Ca. Posts: 632	Re: cut hole in firewall for Painless Wiring Harness? That is just how I did mine. Now just take your time when routing your wires to make the harness.



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06-06-2011, 11:29 PM	#18
Ackattack Senior Member Join Date: Aug 2002 Location: Valley Center KS Posts: 3,524	Re: cut hole in firewall for Painless Wiring Harness? a body saw would do it real easy __________________ Project Bruiser: 68 Pro-Touring C-10 5.3L / 4L60E Project Ironhide: 97 GMC Crew Cab 4x4 Cummins SOLD: '69 GMC 1/2T SWB TBI'd: Project No Buck Assembly Manual Index Sign up Thread!!! Factory Service Manual Index

06-07-2011, 06:36 PM	#19
FLcustom10 Registered User Join Date: Feb 2007 Location: Tallahassee, FL Posts: 322	Re: cut hole in firewall for Painless Wiring Harness? Thanks guys. Bruce here's my build thread. I'll just have to add to it a little at a time. I look forward to reading yours too. http://67-72chevytrucks.com/vboard/s...d.php?t=468335

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