Need help with making a stand alone harness
Thread Starter
On The Tree
Joined: Dec 2014
Posts: 103
Likes: 3
Need help with making a stand alone harness Hello I have a 04 harness out of a Tahoe flex fuel and I've pulled the wires not needed per wiring diagram and have had to shorten some and make others longer .
So I used the wires I've pulled to lengthen some I tryed to use the wire that was close to the same size of wire strands to match if I couldn't find the size I went a little bigger except for 6 wires
15 brown. that goes to computer green connector sayes charge indacator control (alt turn on)?
26 purple ic1 control ?
27 red ic7 control?
68 green ic 5 control ?
69 light blue ic3 control?
75 gray generator field duty cycle signal?
For these wires I didn't have any thing large enough so I had some extra 12 gauge wire that was off my aftermarket wire harness from the head light circuit but the outer sheilding isn't as thick as the factory wires .
I dint know if I should use that or go get some wires with the thicker shielding from the wrecking yard to install.
I'm having to extend the wires 2' and I don't know the factory gauge of wires those circuits ?
Thank you in advance kelly
So I used the wires I've pulled to lengthen some I tryed to use the wire that was close to the same size of wire strands to match if I couldn't find the size I went a little bigger except for 6 wires
15 brown. that goes to computer green connector sayes charge indacator control (alt turn on)?
26 purple ic1 control ?
27 red ic7 control?
68 green ic 5 control ?
69 light blue ic3 control?
75 gray generator field duty cycle signal?
For these wires I didn't have any thing large enough so I had some extra 12 gauge wire that was off my aftermarket wire harness from the head light circuit but the outer sheilding isn't as thick as the factory wires .
I dint know if I should use that or go get some wires with the thicker shielding from the wrecking yard to install.
I'm having to extend the wires 2' and I don't know the factory gauge of wires those circuits ?
Thank you in advance kelly
Thread Starter
On The Tree
Joined: Dec 2014
Posts: 103
Likes: 3
Thank you Efiharness so I can just buy some 18 wire from Napa and install .
Would you know about hooking up a wideband to pin 14 red with black stripe on the green computer connector so hp tuners can datalog it
Is it connected at the gauge or at the wide band sencer connection ?
Would you know about hooking up a wideband to pin 14 red with black stripe on the green computer connector so hp tuners can datalog it
Is it connected at the gauge or at the wide band sencer connection ?
Iirc hptuners changed something so you couldnt pin the wideband to the egr and read it like that. They said it was giving us pro features at the standard price?
If your not using hptuners and know a way for the pcm to read and/or use a wideband id like to see it. Afaik it wont, maybe some1 else will tell us
If your not using hptuners and know a way for the pcm to read and/or use a wideband id like to see it. Afaik it wont, maybe some1 else will tell us
Thread Starter
On The Tree
Joined: Dec 2014
Posts: 103
Likes: 3
Thank you lsxford
I'm planning on getting the hp pro version and I was told to use the ac pressure red with black stripe to hook up to the hp Setup so I was able to data log while I was tuning but the person who told me to do it hasn't been on for a few days hopefully soon he will sign on and reply thanks again kelly
I'm planning on getting the hp pro version and I was told to use the ac pressure red with black stripe to hook up to the hp Setup so I was able to data log while I was tuning but the person who told me to do it hasn't been on for a few days hopefully soon he will sign on and reply thanks again kelly
If you get the pro version you hook it up to the hptuners box. Idt you can wire it to the pcm anymore, but i have yet to purchase hptuners nor have i ever used it. But i read that on hptuners forum
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Why not buy one, it will be cheaper in the long run.
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Verdad Gallardo After finishing my harness, i agree with psi kinda. If its at all in your budget get a premade standalone harness. I wouldnt say its cheaper in the long run to me. But i like doing wiring as strange as that sounds and had nothing in my harness and literally bought some heat shrink and tape for a max of $25.
However it took a ton of time, i estimate 20 hours. It comes down to how much you value your time. But as i said, a new harness is THE way to go if you have the funds, which i didnot.
However it took a ton of time, i estimate 20 hours. It comes down to how much you value your time. But as i said, a new harness is THE way to go if you have the funds, which i didnot.
Thread Starter
On The Tree
Joined: Dec 2014
Posts: 103
Likes: 3
Yes lsxford I don't have the funds right now also and I'm about done with my harness also I have the fuse block connections and relays . I have 24 to 30 hours so far in mine
i have 3 wires on my 04 surburban harness
they are
c2-a11. Gray sayes trailer backup lamp ?
so I'm assuming that it is for the back up lights ?
c2-f11. Dk green park neutral start switch signal?
c2-d3. Lt green park neutral pos switch ?
not sure where to connect these wires.
Im using the factory neutral safety switch
Thank you kelly
i have 3 wires on my 04 surburban harness
they are
c2-a11. Gray sayes trailer backup lamp ?
so I'm assuming that it is for the back up lights ?
c2-f11. Dk green park neutral start switch signal?
c2-d3. Lt green park neutral pos switch ?
not sure where to connect these wires.
Im using the factory neutral safety switch
Thank you kelly
You'll need to run a starter relay if you're using the factory NSS. I don't have my schematics with me but I can tell you which wires to hook up to it in the morning if someone doesn't post them before I get home.
Thread Starter
On The Tree
Joined: Dec 2014
Posts: 103
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Ok ls1nova71 I've looked and looked I hope this tread helps others also.
I have one other wire I forgot about
c100-j pin sayes engine on signal
Dk blue and it goes to the p pin on the alt?
from everything I read it's not needed.
Kelly
I have one other wire I forgot about
c100-j pin sayes engine on signal
Dk blue and it goes to the p pin on the alt?
from everything I read it's not needed.
Kelly
Last edited by Gksportster; Jan 19, 2017 at 02:13 PM.
Thread Starter
On The Tree
Joined: Dec 2014
Posts: 103
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Psi wish I could buy one that was my plan in the beginning but then lost my job and don't have money to buy one then I found a factory one for $20 and picked it up .
I do plan on getting the computer from you guys when I get back to work n have money.
Thank you kelly
I do plan on getting the computer from you guys when I get back to work n have money.
Thank you kelly
As for the starter relay, it will need to be wired as follows:
Using a standard relay you would hook a constant battery power to terminal 30, then on terminal 87 you would hook that wire to the wire that goes to the starter, generally a purple wire on a GM car. Terminal 86 will go to the NSS and hook to the dark green wire in pin 1 on the NSS plug. Pin 12 on the NSS plug is a pink wire and that will hook to your ignition switch, the wire that is hot when the key is in the crank position. Finally, terminal 86 on the relay will be grounded.
The other wires you asked about are the back up lights and the shift interlock, but you wont need that one. On the back up lights you will need to use that trailer light circuit since the actual back up light circuit used the BCM for some reason, but if you wire the gray wire in pin 10 on the NSS plug straight to the lights it will work. You will have to hook up pin 11, a pink wire to an ignition hot source to give them power.
Thread Starter
On The Tree
Joined: Dec 2014
Posts: 103
Likes: 3
Thank you ls1nova71.
I also noticed that their is 2 pink wires going to the neutral safety switch.
I dont remember if both of the pink wires that goes to neutral safety switch was to ignition power ?
thank you kelly
I also noticed that their is 2 pink wires going to the neutral safety switch.
I dont remember if both of the pink wires that goes to neutral safety switch was to ignition power ?
thank you kelly
Staging Lane
Joined: Dec 2014
Posts: 82
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you are down the track with yours, i went the other direction and took the easy route and sent my harness and ecu to this guy on ebay, for the price it was a killer deal, saved me a lot of frustration and he did a quality job, just got it back today.
*non-sponsor link removed*
*non-sponsor link removed*
Last edited by G-Body; Jan 21, 2017 at 05:53 AM. Reason: eBay link to non sponsor
Thread Starter
On The Tree
Joined: Dec 2014
Posts: 103
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Yes 1950 Buick I thank I'm about done with my harness.
If I deleted prndl switch I would be done
I won't be able to test the harness tell I get the computer only one I found around here in the wrecking yards was one blue and red and I need blue green so as soon as I can afford the right one I will get from psi and be able to test my rewrite job
If I deleted prndl switch I would be done
I won't be able to test the harness tell I get the computer only one I found around here in the wrecking yards was one blue and red and I need blue green so as soon as I can afford the right one I will get from psi and be able to test my rewrite job
Pink wires are generally ignition power wires. Without knowing what pins they are on I would guess they are for back up lights and the shift interlock.
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Joined: Mar 2014
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From: Ohio
Iirc hptuners changed something so you couldnt pin the wideband to the egr and read it like that. They said it was giving us pro features at the standard price?
If your not using hptuners and know a way for the pcm to read and/or use a wideband id like to see it. Afaik it wont, maybe some1 else will tell us
If your not using hptuners and know a way for the pcm to read and/or use a wideband id like to see it. Afaik it wont, maybe some1 else will tell us
I'm logging AFR through the AC pin, fuel pressure through the fuel tank pressure pin, and am setting up either backpressure or EGTs through the EGR pin. All on the standard HPT.
I'm going to be upgrading to the Pro just because tuning someone else's car without the wideband pinned in is a PITA. I have a sniffer I put in the tailpipe but I still can't log it on HPT unless I pin it into the PCM. If you only plan on wideband tuning your own car, the Pro version is pointless. If you might do others down the road, get the Pro.