Ls wiring need some help here.

[UP GRADE]

Hello to all, now here we go I'm doing my wiring harness (01 tahoe) and have run into a few problem. On the c2 plug I have all the pink wires label. Is there any other wires that need to be use or do I just cut them. On the c100 plug which wires need to be labeled and which ones are not used. I must admitted this is the first time I have done any wiring and thanks for any help.

[homemade87]

I did almost 100% of my wiring from this site . It all worked out great with no problems . Take a look around at this site . What you need is on there. http://www.lt1swap.com/wiringharness.htm

[UP GRADE]

Hey homemade I have that site. I'm not good with wiring some of it I understand some I don't just not trying to mess this harness up that's why I'm asking about the wires on the connector.

[homemade87]

Originally Posted by UP GRADE

Hey homemade I have that site. I'm not good with wiring some of it I understand some I don't just not trying to mess this harness up that's why I'm asking about the wires on the connector.

Looks like crash has give some good info . What you need is on the site. And take your time and read thru it . I used it for my swap and had no knowledge of what I was doing .The site told me what wire goes where and what wire are need and what wire are not .Mine worked out great.

[Mikebleedsgmc]

My harness was thinned out but the c100 plug is missing! What can i do. And where do i find whats needed? Do the c100 wires go into fuse block?? Thanks

[Crash_OK]

from the LT1SWAP site

http://lt1swap.com/2000harness.htm

Red Connector C2: or GREEN

Pin 9 - Dk Green/White - Fuel Pump Relay Control - This wire the PCM supplies 12v+ to control a relay for fuel pump. PCM will turn on the fuel pump for 2 seconds at initial key on. When the engine cranks or starts, the fuel pump will then continue to run, untill the engine stops, or you shut off the key.

Pin 10 - White - Engine Speed Signal - Tach signal. Stock programming of the PCM will output a 4 cylinder tach signal. When I program the PCM, I can change this signal to a 8 cylinder. This way you don't have to modify your tach.

Pin 33 - Dk Green - Fan 2 Control - some 99-02 harnesses will have a pin here, this was used for the HVAC Recirculation Door control. The PCM would control the A/C recirculation to help cool the a/c system if it got too hot. In an engine swap, programming can be changed to let this control a second cooling fan. Again, PCM supplies a GROUND to run on a relay. You must wire your fans through a relay.

Pin 46 - MIL Control - This is your ''check engine'' light control wire. PCM will supply a GROUND on this wire when the light should be ON.

Pin 50 - Dk Green/White - VSS - This is a signal generated by the PCM, based on information it receives from the vehicle speed sensor located in the transmission. The PCM takes the sensor signal, and calculates the tire size, gear ratio programmed into it, and makes a 4000 pulse per mile signal. This is useful if you want to use a cruise control box. Some speedometers will use this as an input, others, like Autometer's, will hook directly to one wire of the speed sensor in the trans.

After pins are removed, AND some labeled, I start working into the harness to remove un-needed wires that are now removed from the PCM connectors. Some will pull right out, as they went to C100, C152, or C2 Underhood. Pull all the loose wires that go deeper into the harness back past where the original C100, C152 were located. Tightly tape up the wire bundle at this location, as to not let there be too little or too much slack on the wires going to the PCM. Be sure to use masking tape to hold the basic shape of the engine harness. As you progress into the harness, you will find some ground wires that trace back to splice packs. Simply cut the wire up close to the splice pack. Keep 1 or 2 ground wires for when you add the relays and diagnostic port, you will need a ground. DO NOT LET THE HARNESS FALL APART OR GET TANGLED. As I get up to where wires branch out, I will follow that branch out, remove any wires going into it, then tape that branch back up. Only doing one branch at a time.

You can start to cut and label the pink wires from C2 Underhood. See this link and look for the wires highlighted in BLUE. You may find it easier to use a digital volt-ohm meter set to continuity beep mode, in finding where each pink wire goes. This is pretty standard across all Vortec 4.8/5.3/6.0 harnesses: PCM - 2 pink; MAF - 1 pink; TRANS - 1; COILS - 2; INJECTORS - 8; O2 SENSORS 1 EACH;