The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > General Truck Forums > Engine & Drivetrain > LSx Swaps

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 05-09-2020, 03:41 PM   #1
kglowacky
Registered User
 
Join Date: Mar 2020
Location: The Woodlands,Tx
Posts: 555
aftermarket wiring harness

doing a LS swap on my 78 c10. Need some thoughts on a complete aftermarket wiring harness. I need everything Fuse box a/c etc to install with my swap. Has anyone purchased a harness you are happy with? I will need it to be able to run AC and PW from my oem systems looking for a installation that covers all the headlights taillights and interior gauges etc. Does anyone even make a complete kit like this. Thanks

Last edited by kglowacky; 05-09-2020 at 03:46 PM.
kglowacky is offline   Reply With Quote
Old 05-09-2020, 04:37 PM   #2
LS short box
Registered User
 
Join Date: Jun 2015
Location: Carlos MN
Posts: 1,888
Re: aftermarket wiring harness

For a chassis harness I've used a number of Painless universal kits over the years. American Auto Wire gets good reviews also.
For an engine/trans harness I've used Spear Tech and Howell Fuel injection. Both with good success. Howell is a little cheaper. I buy the computer and the harness from the same company so if there is an issue I have one place to call.
LS short box is online now   Reply With Quote
Old 05-09-2020, 06:17 PM   #3
mongocanfly
Post Whore

 
mongocanfly's Avatar
 
Join Date: May 2015
Location: Alabama
Posts: 14,557
Re: aftermarket wiring harness

for the truck side harness.i have American autowire...very good kit
for the engine side Ive used PSI ..I want to try BP engine harness on my next one..ive heard the main wiring is longer and would allow the ECM to be mounted under the seat
__________________
Mongo...aka Greg

RIP Dad
RIP Jesse

1981 C30 LQ9 NV4500..http://67-72chevytrucks.com/vboard/s...d.php?t=753598
Mongos AD- LS3 TR6060...http://67-72chevytrucks.com/vboard/s...34#post8522334
Columbus..the 1957 IH 4x4...http://67-72chevytrucks.com/vboard/s...63#post8082563
2023 Chevy Z71..daily driver
mongocanfly is offline   Reply With Quote
Old 05-09-2020, 08:04 PM   #4
kglowacky
Registered User
 
Join Date: Mar 2020
Location: The Woodlands,Tx
Posts: 555
Re: aftermarket wiring harness

does American give me all the wiring for the dash cluster and gauges, tail lights, door jams, dome lights etc? Does their new fuse box fit in the firewall hole where the factory one did? all wiring except the engine harness??
kglowacky is offline   Reply With Quote
Old 05-09-2020, 08:41 PM   #5
LS short box
Registered User
 
Join Date: Jun 2015
Location: Carlos MN
Posts: 1,888
Re: aftermarket wiring harness

I don't know about American but the Painless fuse block would not fit in the stock firewall hole do to the larger number of fused connections. I suspect American would be the same. Both companies include wires and fuses for all basic stuff like lights, turn signals and such. Also both include wires for AC, power windows and radios.
The dash wiring the kits supply are fused wires for the gauges but not the sensors.
LS short box is online now   Reply With Quote
Old 05-09-2020, 10:15 PM   #6
sprint_9
Registered User
 
sprint_9's Avatar
 
Join Date: Nov 2012
Location: 9
Posts: 862
Re: aftermarket wiring harness

American Auto Wire needs a larger hole in the firewall as well.

I used the AAW chassis harness and was pretty happy with it. I used a BP engine harness but probably wouldn't again, I haven't been happy with it overall. I'd use a Speartech if I did it all over.
sprint_9 is offline   Reply With Quote
Old 05-10-2020, 08:02 AM   #7
derotoreut
Roto Reuter thats the name...
 
derotoreut's Avatar
 
Join Date: Feb 2010
Location: Darien, NY
Posts: 1,847
Re: aftermarket wiring harness

I would use the American Autowire Classic Update. It's no big deal to enlarge the hole. You have to remove the old fuse box anyway. They give you a pattern to use. I've used both AAW and Painless. I prefer the AAW. IMO Painless is anything but painless.
__________________
~ Dan
My 70 K10 SWB build:http://67-72chevytrucks.com/vboard/s...d.php?t=782232
My 71 SWB build:http://67-72chevytrucks.com/vboard/s...d.php?t=651394

1970 SWB Fleet K10 4X4, 5.3L LM7, 4L60E, Dakota Digital RTX, Vintage Air, Ididit tilt
1971 SWB Fleet C10 - Original SWB Arizona truck, new custom restoration project

"Kick out your motor and drive while you're still alive - kick it out!" - Heart 1977
derotoreut is offline   Reply With Quote
Old 05-10-2020, 09:36 AM   #8
nsb29
Senior Member
 
nsb29's Avatar
 
Join Date: Feb 2014
Location: new smyrna beach fl / 29 palms cal
Posts: 1,727
Re: aftermarket wiring harness

I used aaw classic up grade nice kit, but doesn’t come with grommets you have to bye them separately. Don’t understand about enlarging any holes because it uses all original grommets! But you will have to You integrate the to together. I used bp automotive and liked it and it is long enough to go under the seat
__________________
Hand made A/C vent manifolds for 64-66 trucks adapts any aftermarket A/C to OEM vent
nsb29 is offline   Reply With Quote
Old 05-10-2020, 04:39 PM   #9
LS short box
Registered User
 
Join Date: Jun 2015
Location: Carlos MN
Posts: 1,888
Re: aftermarket wiring harness

I don't know what level of project you are doing but on my project I filled the original fuse block hole and then moved the Painless fuse block back a bit from the firewall using a "L" bracket I fabbed. Then I ran all the chassis wiring over the top of the steering column and then made hole it trans tunnel for the wires. Ran the wires forward and back as needed. On my truck you can't any of the chassis wires.
LS short box is online now   Reply With Quote
Old 05-12-2020, 12:28 PM   #10
kglowacky
Registered User
 
Join Date: Mar 2020
Location: The Woodlands,Tx
Posts: 555
Re: aftermarket wiring harness

has anyone used the painless harness 10201 or #10206. Just talked with painless they are trying to sell me the 10206 and say the 10201 would work. the 01 I think a universal harness and really have no reason to think it cant work. Neither has the gauge cluster plug so I would need to use my old one LOL I don't have an old one. Please let me know if anyone can shead some light on this. Thanks
kglowacky is offline   Reply With Quote
Old 05-12-2020, 03:38 PM   #11
skyphix
Registered User
 
Join Date: Sep 2018
Location: Hampden, ME
Posts: 406
Re: aftermarket wiring harness

I can't comment on the chassis harness yet - when it comes time I'll be doing a very stripped out chassis harness (not running the factory dash, eliminating a bunch of unneeded wiring for my stripped out truck) so I plan on using the AAW universal wiring kit.

For my engine harness and PCM, I used PSI. Their support and the quality of their product, in my experience, has been top notch. Truck runs awesome and besides the MAF wiring being too short (I used the factory intake tract... if you used an aftermarket and kept the battery on the passenger side, it would be perfect) which they told me it would be, I didn't have to do anything. I just grabbed an extension for the MAF so I didnt have to cut the harness. I'll be ordering their universal truck pedal soon as well.
__________________
Eric
1980 C10 SWB
2003 Chevy Suburban 2500 LT
skyphix is offline   Reply With Quote
Old 05-12-2020, 04:49 PM   #12
LS short box
Registered User
 
Join Date: Jun 2015
Location: Carlos MN
Posts: 1,888
Re: aftermarket wiring harness

I've used the 21 circuit universal Painless on a number projects. Most were LS swapped projects. I saved all the connectors off the original car/truck harness and the mated them to the Painless harness as needed. Get a wiring diagram for the original truck harness. These trucks are pretty simple. I think the direct Painless harness is configured to plug right in the truck components.
LS short box is online now   Reply With Quote
Old 05-13-2020, 01:10 PM   #13
MDPotter
Senior Member
 
MDPotter's Avatar
 
Join Date: Aug 2018
Location: Western Colorado
Posts: 1,165
Re: aftermarket wiring harness

American Autowire classic update is my preferred route. I don't know of a harness that includes the complete chassis, LS, and fuel pump/fans. Autowire Has extra circuits for modern upgrades like power seats, power locks, etc. or you can use them to power your LS harness and clean things up. Either rework your LS harness yourself or have Speartech do it. Run a separate fuse/relay block for fuel pump and fans.
__________________
1964 Chevy C10 - Gen IV 5.3 Restomod http://67-72chevytrucks.com/vboard/s...d.php?t=768632
1968 GMC C15 - Gen III 6.0 Restomod http://67-72chevytrucks.com/vboard/s...d.php?t=772047
1969 Chevy C10 - Restoration http://67-72chevytrucks.com/vboard/s...d.php?t=809184
1978 Chevy Scottsdale K20
1993 Chevy C1500 - 5.3/T56 swapped
2008 Silverado Duramax
MDPotter is offline   Reply With Quote
Old 05-13-2020, 05:06 PM   #14
kglowacky
Registered User
 
Join Date: Mar 2020
Location: The Woodlands,Tx
Posts: 555
Re: aftermarket wiring harness

I have had my harness reworked and agree with you 100% on running separate systems. My questions are on what have people used. Painless sells a lot of different ones but I cant really see a lot of difference for the 300$ difference they are asking.
kglowacky is offline   Reply With Quote
Old 09-10-2020, 11:03 PM   #15
Scott2
Registered User
 
Join Date: Mar 2015
Location: Castle Rock, CO
Posts: 534
Re: aftermarket wiring harness

For the vehicle wiring, I used Affordable Street Rods - great kit, awesome instructions!

For the engine, From my own experience I would say whatever you do don’t use LS1Swap Garage. My harness went in a black hole and had a heck of a time getting it back. When I did it was not done right. Sent it back and same fight to get it back. My one serious requirement was to leave the emissions connectors - and they’re gone!? He won’t respond to my messages. Guy’s a nightmare and I have to go buy a new harness.
__________________
Scott

______________
my '51 build: http://67-72chevytrucks.com/vboard/s...d.php?t=677979
Scott2 is offline   Reply With Quote
Old 09-15-2020, 08:41 PM   #16
truckdude239
Senior Member
 
truckdude239's Avatar
 
Join Date: Sep 2005
Location: Lewisville, Nc
Posts: 10,216
Re: aftermarket wiring harness

I used the American auto wire classic update kit on my 71 I hate wiring but would use the aaw kit again in a heart beat and had the stock harness for ls engine modified
__________________
David fuller
Ase Certified Mechanic
Click here to help support our board!!


1971 Chevy c-10 under going a 4.8l LSx swap

Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305

2007 Honda Accord my daily 145kmiles
2002 Honda Accord 4 door With 330k(sisters car)
2005 toyota Avalon 228k( brothers car)
2002 Sububran 5.3 245k
2000 Tahoe 5.3l 378

General manager for Marco's Carwash & lube
truckdude239 is offline   Reply With Quote
Old 09-24-2020, 09:22 AM   #17
ewoody625
Registered User
 
ewoody625's Avatar
 
Join Date: Jan 2009
Location: valparaiso,in
Posts: 730
Re: aftermarket wiring harness

I did painless and had my stock harness modified for my 70. I don't think the painless kit was that bad but I have no experience with any other harnesses.
__________________
Eric

70 CST10 long bed in pieces also factory air and cruise(the project)

18 Silverado crew cab 5.3 4x4

My build thread: http://67-72chevytrucks.com/vboard/s...d.php?t=402166
ewoody625 is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 05:37 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com