Conversions & Swaps LSX Engines in Non-LSX Vehicles
Sponsored by:
Sponsored by:

OBD Splitter Harness

Thread Tools
 
Search this Thread
 
Old Sep 25, 2021 | 09:14 AM
  #1  
kwhizz's Avatar
Thread Starter
TECH Fanatic
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Jul 2008
Posts: 1,570
Likes: 173
Default OBD Splitter Harness

Just some added info for everyone......... When doing the LS swap in Chris's car with Dakota Digital parts....... I wanted to be able to use a Scanner, and the OBD plug needed to be plugged into the Dakota control box......So I bought a OBD splitter to achieve both functions.......After Chris took the car on the Power Tour it started doing goofy things,,,,,Half the dash gauges would quit working while driving, then the cooling fans wouldn't turn on.......... Hummm !!!! .......They wired the relays with a switch to get the fans on...... and the gauges would sporadically go out....... Finally got the car home and found out the Splitter harness was the problem as it wasn't transmitting all the info thru the harness......Took it out and everything works perfectly now...... Defective splitter harness...... Just passing the info along !!!!

Ken
Reply
Old Sep 25, 2021 | 08:30 PM
  #2  
chuckd71's Avatar
TECH Fanatic
15 Year Member
Photogenic
Photoriffic
Liked
iTrader: (23)
 
Joined: Jul 2010
Posts: 1,768
Likes: 22
From: Nashville / Tampa
Default

I bought a splitter to use to get a tach signal for my LT swap. Fingers crossed it will work out
Reply
Old Sep 25, 2021 | 10:32 PM
  #3  
showdog75's Avatar
TECH Fanatic
10 Year Member
Liked
Loved
Community Favorite
iTrader: (8)
 
Joined: Mar 2014
Posts: 1,152
Likes: 252
From: Hixson TN
Default

I bought a Autometer obd splitter and had issues as well. I have a Dakota Digital bim module and I thought I'd use the splitter so I'd have a open obd port but now I just unplug the bim module when needed.
Reply
Old Sep 26, 2021 | 10:03 AM
  #4  
67Skylark's Avatar
TECH Apprentice
10 Year Member
Photogenic
Photoriffic
Shutterbug
 
Joined: Nov 2011
Posts: 346
Likes: 7
From: Tampa, FL
Default

Is this just an issue with Dakota Digital?
...
I have had an OBD splitter in my kids 2018 Challenger for the past two years in order the have a Linxup tracker and also keep the standard port in the factory location, it has never had any issues. I have just (< than 10 miles ago) added a splitter in my LY6 (ECM = E38) to allow for a hidden tracker, no tracker yet, I haven't had any issues with the challenger yet.
Reply
Old Sep 26, 2021 | 11:42 AM
  #5  
aknovaman's Avatar
TECH Addict
15 Year Member
Liked
iTrader: (7)
 
Joined: Apr 2007
Posts: 2,012
Likes: 111
From: Hog Back, KS
Default

you guys talking about these?


https://www.ebay.com/itm/25463342982...Cclp%3A2334524
Reply
Old Sep 27, 2021 | 06:12 AM
  #6  
kwhizz's Avatar
Thread Starter
TECH Fanatic
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Jul 2008
Posts: 1,570
Likes: 173
Default

Yes !!!!.....
Reply
Old Sep 27, 2021 | 02:25 PM
  #7  
1964SS's Avatar
TECH Fanatic
10 Year Member
Liked
Loved
Community Favorite
iTrader: (1)
 
Joined: Aug 2012
Posts: 1,539
Likes: 84
From: Mesa, Arizona
Default

Why not just wire up two obd ports? only a few wires being used on them anyway.
Reply
Old Sep 28, 2021 | 10:40 AM
  #8  
Jimbo1367's Avatar
TECH Senior Member
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Jul 2009
Posts: 8,032
Likes: 661
Default

I believe Holley or DD recommends not using them for that exact reason. Hook it up just to scan then remove
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-1

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-2

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-3

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-4

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-5

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-6

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
story-7

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-8

10 Camaros You Should Never Buy

 
story-9

10 LS Engine Myths That Refuse to Die

 Verdad Gallardo
Old Oct 10, 2022 | 05:32 PM
  #9  
kwhizz's Avatar
Thread Starter
TECH Fanatic
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Jul 2008
Posts: 1,570
Likes: 173
Default

Update..... Jeff and Judy's 1955 Pontiac Station wagon that was LS swapped two years ago had a problem while on Crusin the Coast down in Biloxi, Ms.......... Jeff called and told me the car overheated and the fans wouldn't turn on........ Hummm!!!..... I asked what other symptoms the car was showing...... He told me the Temp gage and the oil pressure didn't work........ (Same symptoms as Chris's car had)...... Told Jeff to remove the OBD harness...... He did and everything works again...... Gary's Biscayne had the same problem also...... Just Say'in !!!!!!
Reply
Old Oct 10, 2022 | 05:35 PM
  #10  
kwhizz's Avatar
Thread Starter
TECH Fanatic
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Jul 2008
Posts: 1,570
Likes: 173
Default

Amazon Amazon
Reply
Old Oct 11, 2022 | 09:08 PM
  #11  
jetech's Avatar
TECH Fanatic
Veteran: Air Force
5 Year Member
Liked
Community Favorite
 
Joined: Jan 2018
Posts: 1,250
Likes: 239
From: Dade City, Fl.
Default

I tried the same thing with my '71 Camaro 6.0l swap with Dakota Digital gauges. I contacted DD tech support and they told me the signal gets "linked" to a connection that it will communicate with. Usually only one. Here is an explanation from the EFI forum https://forum.efilive.com/showthread...-the-OBD2-data See Post #6
Reply
Old Oct 12, 2022 | 09:01 AM
  #12  
kwhizz's Avatar
Thread Starter
TECH Fanatic
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Jul 2008
Posts: 1,570
Likes: 173
Default

Ahh!!!!!....... Makes sense
Reply
Old Oct 12, 2022 | 09:46 AM
  #13  
BlueMagicSS's Avatar
TECH Enthusiast
iTrader: (4)
 
Joined: Dec 2008
Posts: 524
Likes: 1
From: Bay Area, CA
Default

From my experience it doesn't seem like the OBD signal likes to be split with the Dakota. I know for a fact you can't use a splitter and Tune the PCM, at least with HP Tuners, the BIM module has to be unplugged.
Reply
Old Oct 12, 2022 | 01:14 PM
  #14  
Senna's Avatar
On The Tree
iTrader: (1)
 
Joined: Nov 2016
Posts: 166
Likes: 2
From: San Jose CA
Default

Just to add some info to the topic. On my Chevelle With a GM computer and DD gauges. I had Speartech harness built with two OBD II ports with the hopes of being able to access the the available port for diagnostics wile leaving the the DD gauge plugged into the other port, The tech at Speartech advised this would work. In the end, it didn't work and I have to Unplug the DD to use a scanner.

Reply
Old Oct 14, 2022 | 12:50 PM
  #15  
LilJayV10's Avatar
TECH Senior Member
15 Year Member
Liked
Loved
Community Favorite
iTrader: (39)
 
Joined: Apr 2007
Posts: 9,711
Likes: 999
From: Evansville,IN
Default

I've never had an OBD splitter work correctly for anything. Just my experience.
Reply




All times are GMT -5. The time now is 11:52 PM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-3
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-4
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE