Forced Induction Superchargers | Turbochargers | Intercoolers

Question about installing A/F gauge

Thread Tools
 
Search this Thread
 
Old Aug 27, 2005 | 05:02 PM
  #1  
ChevyChad's Avatar
Thread Starter
8 sec potential, 12 sec slip
iTrader: (50)
 
Joined: Apr 2002
Posts: 4,092
Likes: 2
From: Savannah, GA
Default Question about installing A/F gauge

I'm installing my gauges, and got all the wiring ran and pretty much done. I only have 1 wire left that I don't know where it goes. It is the violet wire on my autometer A/F ratio gauge, and it says it is supposed to go to the signal wire that goes from the 02 sensor plug to the computer. Only problem I don't know is which one is that wire? What color is it, and what is the # slot it goes into at the PCM? Should I just put a tap right there at the PCM in the engine bay, or is there a closer place under the knee bolster? Thanks for any help.
Reply
Old Aug 27, 2005 | 06:27 PM
  #2  
Ferocity02's Avatar
TECH Senior Member
iTrader: (60)
 
Joined: Apr 2003
Posts: 9,397
Likes: 4
Default

You need to tap into the signal wire coming off the front passenger side oxygen sensor. You can tap into it by the sensor or up by the PCM. Trace your oxygen sensor wires up from the sensor. The wire you need to tap into the violet also. On my car, there is a bundle of wires near the PCM that had the wire in it. There were only two violet wires in this bundle. The larger one goes to the starter and the small one is the one you want to tap into.
Reply
Old Aug 27, 2005 | 07:25 PM
  #3  
ChevyChad's Avatar
Thread Starter
8 sec potential, 12 sec slip
iTrader: (50)
 
Joined: Apr 2002
Posts: 4,092
Likes: 2
From: Savannah, GA
Default

Thanks man
Reply
Old Aug 27, 2005 | 07:56 PM
  #4  
XxXTransAmXxX's Avatar
TECH Resident
iTrader: (12)
 
Joined: Jul 2004
Posts: 987
Likes: 1
From: Georgetown, IL 61846-1105
Default

Damn I was coming for ya buddy lol, anyways glad you got it to work, and have fun taking your gf out to eat with a working gauge
Reply
Old Aug 28, 2005 | 03:10 PM
  #5  
ChevyChad's Avatar
Thread Starter
8 sec potential, 12 sec slip
iTrader: (50)
 
Joined: Apr 2002
Posts: 4,092
Likes: 2
From: Savannah, GA
Default

Okay- went out to install the 1 remaining wire, and found like 5 solid purple wires going into the PCM. And there were a couple more with different colored lines on them... Soooo which of the 5 do I use? The pin# that it plugs into the PCM would be great if anyone knows... TIA
Reply
Old Aug 28, 2005 | 03:36 PM
  #6  
XxXTransAmXxX's Avatar
TECH Resident
iTrader: (12)
 
Joined: Jul 2004
Posts: 987
Likes: 1
From: Georgetown, IL 61846-1105
Default

Chad, if you don't find out, I Will keep diggin for ya, but if you don't find out you can always just follow it from where it plugs into the O2 sensor at, or you can just splice in @ the 02....
Reply
Old Aug 28, 2005 | 04:30 PM
  #7  
ChevyChad's Avatar
Thread Starter
8 sec potential, 12 sec slip
iTrader: (50)
 
Joined: Apr 2002
Posts: 4,092
Likes: 2
From: Savannah, GA
Default

Well, I already ran the wire to the PCM & cut it, so I'd really like to just splice it into the PCM there and not have to take apart my interior panels again to re route it... I may just have to jack it up and trace it tomorrow if I can't find out tonight.
Reply
Old Aug 28, 2005 | 04:44 PM
  #8  
Ferocity02's Avatar
TECH Senior Member
iTrader: (60)
 
Joined: Apr 2003
Posts: 9,397
Likes: 4
Default

Trace it. The bundle where I tapped into wasn't RIGHT next to the PCM. Probably like 6" away near the AIR tube. The wires from the O2 sensor run up right next to the passenger side header. You shouldnt need to jack it up.
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 Aug 28, 2005 | 05:04 PM
  #9  
ChevyChad's Avatar
Thread Starter
8 sec potential, 12 sec slip
iTrader: (50)
 
Joined: Apr 2002
Posts: 4,092
Likes: 2
From: Savannah, GA
Default

Okay, I just looked and found the loom I think you are reffering to. It runs right by the AIR tube on the p/s. There are 2 purple wires, but they both appear to be the same size. 1 is all purple, and the other has a white stripe on it. Do you happen to know which one it is?
Reply
Old Aug 28, 2005 | 07:01 PM
  #10  
Ferocity02's Avatar
TECH Senior Member
iTrader: (60)
 
Joined: Apr 2003
Posts: 9,397
Likes: 4
Default

Okay... see if this helps. In the bundle I am talking about, at least on my car, there are 10 wires. Violet large(about 4x larger than the other wires), violet small(the O2 sensor signal wire), pinkish/red, beige, black, black w/ white stripe, brown, blue w/ white stripe, yellow w/ black stripe, and green. This bundle is coming up from under the car running next to the passenger side header. It should have some heat wrap on it. It has the oxygen sensor wires, starter wires, and I think some of the ABS wires. The violet wire I tapped into had no stripe on it. It was a solid violet small wire. You are probably going to have to trace it, although I am willing to guess the solid violet wire on your car is probably the right one. You have to be sure you are tapping into the right one. If you hook the gauge up to a 12v source, it will toast it. The voltage of the signal wire bounces back and forth between 0 and 1volt. If you have a volt meter you can test to see which one is right, but you of course have to strip a little bit of the wire. Your best bet at this point is to trace the wire.
Reply
Old Aug 28, 2005 | 07:08 PM
  #11  
ChevyChad's Avatar
Thread Starter
8 sec potential, 12 sec slip
iTrader: (50)
 
Joined: Apr 2002
Posts: 4,092
Likes: 2
From: Savannah, GA
Default

Thanks for all the help. HEre is the pic I took earlier and forgot to post with my last reply:



I am pretty sure this is the wrong bundle of wires according to your last reply. I do think I recall seeing one loom with heat wrap around it tho. I'll check that one for the signal wire you are reffering to.

Thanks again for all your help man
Reply
Old Aug 28, 2005 | 07:13 PM
  #12  
Ferocity02's Avatar
TECH Senior Member
iTrader: (60)
 
Joined: Apr 2003
Posts: 9,397
Likes: 4
Default

The loom i am talking about is like 1/2" stuff, and is under the A/C lines.

You need to clean your poor engine!
Reply
Old Aug 28, 2005 | 09:09 PM
  #13  
ChevyChad's Avatar
Thread Starter
8 sec potential, 12 sec slip
iTrader: (50)
 
Joined: Apr 2002
Posts: 4,092
Likes: 2
From: Savannah, GA
Default

Okay- I am pretty sure I know the one you're talking about.

LOL! I knew I shouldn't have posted that pic. Good thing this isn't the appearance forum
Reply
Old Aug 29, 2005 | 04:09 AM
  #14  
JMBLOWNWS6's Avatar
9 Second Club
iTrader: (17)
 
Joined: Nov 2002
Posts: 4,997
Likes: 0
From: New Braunfels ,Tx
Default

I would never cut into my harness for that. It can mess with your voltage and give inncorrect readings to the pcm. Plus its just a light show. I was just going to tap it but I spent $20 on the casper a/f pigtail because I dont like cutting into my harness. https://ls1tech.com/forums/showpost....66&postcount=2
Reply
Old Aug 29, 2005 | 08:17 AM
  #15  
ChevyChad's Avatar
Thread Starter
8 sec potential, 12 sec slip
iTrader: (50)
 
Joined: Apr 2002
Posts: 4,092
Likes: 2
From: Savannah, GA
Default

Thanks for your concern JMBLOWNWS6. That looks like a good tool, but its doing the exact same thing as tapping into the harness- you just get some fancy connections. This wire obviously is a voltage controlled signal wire. And all parallel wires in a circuit have the same voltage. The current will drop, but that does not matter since all the computer senses is the voltage, so I should be okay tapping into the wire.
Reply




All times are GMT -5. The time now is 06:54 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