Wiring Harness Questions
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Teching In
Joined: Jul 2016
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Wiring Harness Questions New to the board. Hoping for some help with wiring harness questions.
I am building a 71 Camaro. I am putting an LQ4 Modded with Cam, Headers, & Heads. Going to run the 4l80 Trans. with Yank converter. Now to the questions. I am trying to cut down my harness to make it a stand alone harness. I think I need my O2 sensors & Knock Sensor. Now! Should I leave my temp sender, oil pressure sender, & fuel pump connector hooked up to the computer. I am planning on putting in a Dakota Digital gauge cluster. I would say electric fans but my vehicle did not have electric fans. Will install it as a stand alone circuit. Also where do you install the data port.
I am new to the LS scene and trying to play catch up. Thanks for any help you can offer.
I am building a 71 Camaro. I am putting an LQ4 Modded with Cam, Headers, & Heads. Going to run the 4l80 Trans. with Yank converter. Now to the questions. I am trying to cut down my harness to make it a stand alone harness. I think I need my O2 sensors & Knock Sensor. Now! Should I leave my temp sender, oil pressure sender, & fuel pump connector hooked up to the computer. I am planning on putting in a Dakota Digital gauge cluster. I would say electric fans but my vehicle did not have electric fans. Will install it as a stand alone circuit. Also where do you install the data port.
I am new to the LS scene and trying to play catch up. Thanks for any help you can offer.
Welcome to the forum. As stated Lt1swap will have all the pinout information you are looking for. You want to keep your front O2 sensors, knock sensors, temp sensor and fuel pump control. You can also pin your harness for the electric fan control and have it enabled when you get your vats removed and PCM tuned. If you plan on using electric fans I highly suggest using the computer control rather then the stand alone units. The stand alone setups are never as reliable.
Last edited by 1964SS; Jul 18, 2016 at 03:10 PM.
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Joined: Mar 2014
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From: Ohio
I convert to electric fans in my swaps. Stock F-body LS1 fans can be had for less than $50. You can run them both as single speed with a 40-amp fuse. The ECU will control the relay and turn the fans on/off at whatever temps you decide. Very nice to have. Mechanical fans are loud and require large shrouds. You can get some nice shroud/fan combos on ebay that fit your stock radiator fairly well.
Same for fuel pump. Leave the relay control wire there. Its so nice having the ECU turn on/prime your pumps. No toggle switches, no constant fuel feed by turning it on with ignition so that it runs with the key on even with the car off.
You don't NEED knock sensor or O2 sensors. Knock sensors are recommended for safe tuning, but not a necessity. Same with O2 sensors. You can use a wideband and tune for open loop and not need any O2 sensors. The Chevelle I finished last week used O2 sensors and a MAF for closed loop driving. It honestly doesn't drive any better than my Speed Density tuned (No MAF) turbocharged Nova that has no O2 sensors either, just a wideband.
You DO need the coolant temp sensor. The car will not run without it. Same for an IAT sensor, but if you run a stock MAF, it will likely have the sensor in it, otherwise you need to buy a sensor and locate it somewhere.
Oil pressure sensor, the oil level sensor in the pan can both be deleted. They won't do much for you in a swap. You can also delete A/C wiring, EGR, EVAP (including fuel tank pressure wires), downstream O2 sensors, alternator control wires, tank level gauge wires, and PRNDL switch wires if you plan to delete it from your trans.
Same for fuel pump. Leave the relay control wire there. Its so nice having the ECU turn on/prime your pumps. No toggle switches, no constant fuel feed by turning it on with ignition so that it runs with the key on even with the car off.
You don't NEED knock sensor or O2 sensors. Knock sensors are recommended for safe tuning, but not a necessity. Same with O2 sensors. You can use a wideband and tune for open loop and not need any O2 sensors. The Chevelle I finished last week used O2 sensors and a MAF for closed loop driving. It honestly doesn't drive any better than my Speed Density tuned (No MAF) turbocharged Nova that has no O2 sensors either, just a wideband.
You DO need the coolant temp sensor. The car will not run without it. Same for an IAT sensor, but if you run a stock MAF, it will likely have the sensor in it, otherwise you need to buy a sensor and locate it somewhere.
Oil pressure sensor, the oil level sensor in the pan can both be deleted. They won't do much for you in a swap. You can also delete A/C wiring, EGR, EVAP (including fuel tank pressure wires), downstream O2 sensors, alternator control wires, tank level gauge wires, and PRNDL switch wires if you plan to delete it from your trans.
Thread Starter
Teching In
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My harness is not wired for electric fans. If I understand correctly. If I add the wires in the correct Pin location they can activate it when they remove the VATS and whatever else I need. (That's the route I would like to go with the Fans) I did not know that was an option. I have read a little on removing the knock sensors and the O2 sensors. Sounds a little risky for me on my first project. Think I will stay with the safer route this time if I can. I have been dealing with Texas Speed on the Cam Kit. I am going to run the Tsunami cam. I degreed it in last weekend. Going to use the PCM to control fuel pump relay. I am going to use the Dakota Digital dash cluster and was reading on another thread that Dakota makes an adapter to tie into the PCM for my oil pressure, Temp, RPM, and Odometer. Glad to have found this website.
The biggest problem I have is not knowing what questions to ask.
You have already brought up somethings I didn't know I could do.
Big Thanks to you all! If you can think of anything you have run across that would be helpful. PLEASE SHARE! LOL
The biggest problem I have is not knowing what questions to ask.
You have already brought up somethings I didn't know I could do.
Big Thanks to you all! If you can think of anything you have run across that would be helpful. PLEASE SHARE! LOL
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Joined: Mar 2014
Posts: 7,192
Likes: 109
From: Ohio
The harness isn't setup for electric fans, no. But its super easy to.
All you do is take a random wire that you de-pinned from the ECU connector, and shove it into Pin 42 on the blue connector. It will take a bit of effort to make it pop through the rubber grommet since there wasn't originally a wire in it. This wire will now go to the ground on the fan relay, and the ECU will ground the relay when it hits whatever temps you set it to.
Then in HPTuners you just go into System -> Fans and change the 'On ECT' to whatever temp you want the fans to kick on, and the 'Off ECT' to whatever temp you want them to kick back off. I usually do on at 190 and off at 180, or on at 205, off at 195, depending on the setup and thermostat. Shouldnt take more than 5 mins total to pin in a wire and then enable fans in HPTuners. Your ECU will now do all of the work when it comes to cycling the fans.
As for removing the O2 sensors, its not really a bad idea. All they do is allow for closed loop driving (better gas mileage as the sensors tune your fuel trims). Other than that, narrowband sensors are extremely inaccurate for tuning and should be ignored completely for wide open throttle tuning. Thats why I decided to just use my wideband and tune my cruising AFRs on the wideband and delete the O2 sensors. They definitely aren't a safety concern.
Knock sensors are more of a safety concern. No reason to delete them unless you're going with a carb. I have deleted them on swaps before because of a broken sensor, or leaking valley cover, but I knew my tune was safe and didn't worry too much about seeing any knock.
All you do is take a random wire that you de-pinned from the ECU connector, and shove it into Pin 42 on the blue connector. It will take a bit of effort to make it pop through the rubber grommet since there wasn't originally a wire in it. This wire will now go to the ground on the fan relay, and the ECU will ground the relay when it hits whatever temps you set it to.
Then in HPTuners you just go into System -> Fans and change the 'On ECT' to whatever temp you want the fans to kick on, and the 'Off ECT' to whatever temp you want them to kick back off. I usually do on at 190 and off at 180, or on at 205, off at 195, depending on the setup and thermostat. Shouldnt take more than 5 mins total to pin in a wire and then enable fans in HPTuners. Your ECU will now do all of the work when it comes to cycling the fans.
As for removing the O2 sensors, its not really a bad idea. All they do is allow for closed loop driving (better gas mileage as the sensors tune your fuel trims). Other than that, narrowband sensors are extremely inaccurate for tuning and should be ignored completely for wide open throttle tuning. Thats why I decided to just use my wideband and tune my cruising AFRs on the wideband and delete the O2 sensors. They definitely aren't a safety concern.
Knock sensors are more of a safety concern. No reason to delete them unless you're going with a carb. I have deleted them on swaps before because of a broken sensor, or leaking valley cover, but I knew my tune was safe and didn't worry too much about seeing any knock.
Thread Starter
Teching In
Joined: Jul 2016
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I have been kicking around the idea of purchasing the hp tuners program. I am an old school carb guy that doesn't know a lot about the comp side of tuning. I don't know if I should just pay someone to give me a mail order tune or try it myself. I am very mechanical. None of my buddies are tuners. Have watched some videos on youtube, and it doesn't look all that hard.
Thanks!
Thanks!
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The harness isn't setup for electric fans, no. But its super easy to.
All you do is take a random wire that you de-pinned from the ECU connector, and shove it into Pin 42 on the blue connector. It will take a bit of effort to make it pop through the rubber grommet since there wasn't originally a wire in it. This wire will now go to the ground on the fan relay, and the ECU will ground the relay when it hits whatever temps you set it to.
Then in HPTuners you just go into System -> Fans and change the 'On ECT' to whatever temp you want the fans to kick on, and the 'Off ECT' to whatever temp you want them to kick back off. I usually do on at 190 and off at 180, or on at 205, off at 195, depending on the setup and thermostat. Shouldnt take more than 5 mins total to pin in a wire and then enable fans in HPTuners. Your ECU will now do all of the work when it comes to cycling the fans.
As for removing the O2 sensors, its not really a bad idea. All they do is allow for closed loop driving (better gas mileage as the sensors tune your fuel trims). Other than that, narrowband sensors are extremely inaccurate for tuning and should be ignored completely for wide open throttle tuning. Thats why I decided to just use my wideband and tune my cruising AFRs on the wideband and delete the O2 sensors. They definitely aren't a safety concern.
Knock sensors are more of a safety concern. No reason to delete them unless you're going with a carb. I have deleted them on swaps before because of a broken sensor, or leaking valley cover, but I knew my tune was safe and didn't worry too much about seeing any knock.
All you do is take a random wire that you de-pinned from the ECU connector, and shove it into Pin 42 on the blue connector. It will take a bit of effort to make it pop through the rubber grommet since there wasn't originally a wire in it. This wire will now go to the ground on the fan relay, and the ECU will ground the relay when it hits whatever temps you set it to.
Then in HPTuners you just go into System -> Fans and change the 'On ECT' to whatever temp you want the fans to kick on, and the 'Off ECT' to whatever temp you want them to kick back off. I usually do on at 190 and off at 180, or on at 205, off at 195, depending on the setup and thermostat. Shouldnt take more than 5 mins total to pin in a wire and then enable fans in HPTuners. Your ECU will now do all of the work when it comes to cycling the fans.
As for removing the O2 sensors, its not really a bad idea. All they do is allow for closed loop driving (better gas mileage as the sensors tune your fuel trims). Other than that, narrowband sensors are extremely inaccurate for tuning and should be ignored completely for wide open throttle tuning. Thats why I decided to just use my wideband and tune my cruising AFRs on the wideband and delete the O2 sensors. They definitely aren't a safety concern.
Knock sensors are more of a safety concern. No reason to delete them unless you're going with a carb. I have deleted them on swaps before because of a broken sensor, or leaking valley cover, but I knew my tune was safe and didn't worry too much about seeing any knock.
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Verdad Gallardo Restricted User
Joined: Mar 2014
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From: Ohio
As long as your tune is good, it doesn't make a huge difference in drivability. I tuned mine in 100 degree heat and then drove it all winter in sub-freezing temps. It drove excellent.
The only hard part is tuning it for the altitude readings you'll be seeing. You can't exactly tune for them 100% unless you are there. Until then, its just a guess.
LOTS of OEM cars are speed density from the factory and they work great.
The only hard part is tuning it for the altitude readings you'll be seeing. You can't exactly tune for them 100% unless you are there. Until then, its just a guess.
LOTS of OEM cars are speed density from the factory and they work great.
Speed density just means it doesnt have a MAF, but all cars have oxygen sensors otherwise youre always running open loop. So basically its just set for one area, and if you were to try to drive to , say the tip of Pikes Peak, then yeah, it'll run like **** up there. Thats the reason I went to fuel injection, I cant see the benefit of not taking full advantage of it.
Gotcha, I figured you had to have the O2's for compensation. I know what your talking about when you say run like ****. I love my fuel injection now, I drove to a car show last year up in Pinetop and loved the drive. No more carb crap to deal with. Now I just smile and listen to all the others bitch about there car not running well LOL