Wiring harness questions

[ronzmtrwrx]

I am trying to sort out some issues on a friends truck with a 2003 5.3/4L60e drivetrain. It's had too many hands laid on it and I'm just trying to debug it. I'd like to start by finding out whose harness they used for the swap. I can't make out the logo, but I'm sure someone here will. Problems I'm trying to correct are: someone wired up the electric fans to come on as soon as you turn the key. Not run through a sensor or anything. I want to find the wire from the ecm to activate the fan relays. They also wired up the Painless harness for the truck itself without any neutral safety switch. I want to wire in a relay utilizing the nss on the trans. At the same time, I'd like to utilize the backup lamp portion of that switch to wire those in. It has the old style two plug connectors and the 4 wire plug labeled with the logo and "trans range sensor" is ran back to the ecm for the pnp function. The other 7 wire plug only has one wire coming out going back to ecm. The rest of the holes are empty. It is labeled with the logo and says "park neutral sensor". I would appreciate some help with an accurate pin out and guidance on wiring in and out of the 7wire plug to straighten out these issues. Thanks in advance. Ron

[mongocanfly]

Is that logo on all the wiring or just one spot?...any marking on the fuse block?....kinda looks like it says E3 ,but I cant be sure
Ls1nova (Eric) may be able to answer your wiring issues...all mine are manuals....

[ronzmtrwrx]

Thanks. That logo is on all the plugs. It looks like a circle and that looks like an & symbol to me. Like its ---&---- but the writing circling it is faded too much to make it out. Nothing at all on the little fuse block. It's just two 4 fuse blocks side by side for just the engine control. The truck itself has a Painless harness (sorta) installed. 😆

[ls1nova71]

That "&" looks a lot like it's from the old Street & Performance logo. They were probably the first company to start selling LS harnesses but they closed several years ago when the owner passed away.

[mongocanfly]

....s&p wiring...here's their logo....
Looks like they may still exsist.....https://s-pautomotive.com/product/wi...ness-services/

[ronzmtrwrx]

Originally Posted by ls1nova71

That "&" looks a lot like it's from the old Street & Performance logo. They were probably the first company to start selling LS harnesses but they closed several years ago when the owner passed away.

I believe you are right. Don’t know why I didn’t think of them. I saw them at a few shows a year or two after Mark passed away, but didn’t know whatever happened to them after that.
Posted via Mobile Device

[ls1nova71]

Its pretty hard to find the Street & Performance logo online these days, but I did manage to locate one, and I'm sure that's what the harness is now. As for hooking up the NSS and back up lights, you will have to add the wires back into the NSS plugs where the wires are missing. There are two plugs, and they have letters on them for pin locations. You should have one plug with the following wires- A- black with white stripe, B- gray, C- white and D- yellow. Then the other plug just has a black with white stripe wire in pin D. Is that what you have?

[ronzmtrwrx]

I will check in the morning. I think it is but need to verify colors.

[ronzmtrwrx]

Originally Posted by ls1nova71

Its pretty hard to find the Street & Performance logo online these days, but I did manage to locate one, and I'm sure that's what the harness is now. As for hooking up the NSS and back up lights, you will have to add the wires back into the NSS plugs where the wires are missing. There are two plugs, and they have letters on them for pin locations. You should have one plug with the following wires- A- black with white stripe, B- gray, C- white and D- yellow. Then the other plug just has a black with white stripe wire in pin D. Is that what you have?

You are correct. That’s exactly what’s there. Now I need to know which spaces to re pin and proceed. I figure on adding a relay activated by the nss for the start function. I also want to send 12v to the nss and grab the backup lamp output to send to the rear. Once those issues are solved, I want to look at finding the ground coming out of the ecm to activate my fan relays via ground. The truck has two 12” fans. (Pushers) I’ve been told it’s a blue wire pin 42. Is that correct?
I think I read somewhere that it might be possible to control them individually by using another wire pin 33 ? Thanks for the assistance. Ron

[FAKKY]

If its a BlueGreen C1/C2

===============================
http://lt1swap.com/2004vortec_pcm.htm

FAN1
Blue 42-- -- Not Used - ADD PIN HERE FOR FAN 1 RELAY CONTROL. 2005+ may already have fan relay pins installed


FAN2
Green 33 -- -- Not Used - ADD PIN FOR FAN 2 RELAY CONTROL
===============================


For a Red/Blue PCM

===============================
http://lt1swap.com/99-02_vortec_pcm.htm


Blue 42 -- -- Not Used - ADD PIN HERE FOR FAN 1 RELAY CONTRO

RED 33 DK GRN 1614 HVAC Recirculation Door Control (KEEP PIN HERE FOR FAN 2 RELAY CONTROL)

===============================

[ls1nova71]

Originally Posted by ronzmtrwrx

I want to look at finding the ground coming out of the ecm to activate my fan relays via ground. The truck has two 12” fans. (Pushers) I’ve been told it’s a blue wire pin 42. Is that correct?
I think I read somewhere that it might be possible to control them individually by using another wire pin 33 ? Thanks for the assistance. Ron

Yes, that's correct, but you will have to have the computer set up for them because an '03 wont already be that way. Also, if you can, move the fans behind the radiator, they work much better there.

[ls1nova71]

The wires you'll need to add will be on the C2 connector on the NSS, it will be the bigger one with only the one black/white wire now. I'll give you the factory colors in case you want them. Pin E pink will come from the ignition switch, the one that's hot when cranking the starter. The factory uses a 10a fuse on this wire. Pin G is green and goes to the starter relay, terminal 86. The remainder of the starter relay connections are, 85 to ground, 30 constant battery power, usually with a 40a fuse and 87 to the starter solenoid.

The back up lights are on the same plug, pink wire (ignition hot) on pin C then pin F gray to the back up lights.

[FAKKY]

Originally Posted by ls1nova71

The wires you'll need to add will be on the C2 connector on the NSS, it will be the bigger one with only the one black/white wire now. I'll give you the factory colors in case you want them. Pin E pink will come from the ignition switch, the one that's hot when cranking the starter. The factory uses a 10a fuse on this wire. Pin G is green and goes to the starter relay, terminal 86. The remainder of the starter relay connections are, 85 to ground, 30 constant battery power, usually with a 40a fuse and 87 to the starter solenoid.

The back up lights are on the same plug, pink wire (ignition hot) on pin C then pin F gray to the back up lights.

Eric - We really need to get this information in that thread you had put into the FAQ section. I'll reach out and ask if we can.

Please dont fall over and hurt yourself until then ... in fact - stay home ....
- john

[ls1nova71]

I suppose I could make a new thread with just this info and maybe some schematics. Cant stay home though, work wouldn't like that. Unless you want to pay me to stay home, then by all means I would! LOL!

[ronzmtrwrx]

Thanks a ton for the help. I would like to move the fans but there’s just simply not enough real estate between the radiator and engine/pulleys. What’s the best source for the new pins that I’ll need, both for the ecm plugs as well as the two different types on the nss plug ?