tan wires on the ls1 harness

[jonus079]

well first off i bought a harness that was modified for stand alone use over a year ago. i cant remeber what company made it but it looked very professional. it was for an automatic tranmsision but it was so cheap i couldnt pass it up and i figured i could just remove the automatic transmission wires except for the speed sensor. yesterday and today i began to take out the automatic wiring and so far so good. now im begining to shorten some parts and lengthen others to make it fit more cleanly in the engine capartment ment.

 

my question: its seems like whoever modified the harness simply spliced all the tan wires (senor grounds) together and then from there ran wires off to individual sensors. is this ok? or should i trace the ground back to the pcm (what a huggggge pain that would be)? i wouldn't think it matters as they are all just grounds for the sensors.

[VinhZXT]

There aren't many TAN wires on an Fbody harness. 1 is the signal for the oil pressure sensor and a couple more for the heated O2 sensors. All the sensors get signals from the PCM and the PCM gets feed back from the sensors. I don't understand why would he wants to connect one side to ground? I guess you can leave it the way it is and try to start the car up. Once the car is running you can find out quickly whether you have a problem or not by reading the DTCs off the PCM. If you need the wiring diagram let me know.

[jonus079]

ok i checked again. there are 5 tan wires. 1 for the oil pressure sender like you said and 1 for each o2 sensor. my harness still has all 4 o2 sensors connect. im only going to be running 2 o2 sensors so ill take sensor 2 off each bank. i wont be using the stock oil pressure sender also.

 

now that i think about it that will only leave me with 2 tan wires so i might as well trace them back to the pcm and connect them to the right port. i think the way it is currently wired is fine but it pretty easy to trace back 2 wires so why not...