Question on 05 5.3L harness

[dropd80s]

I’m going through and getting my harness ready for the standalone conversion and have one question so far. I have found all necessary truck side connections that need to be made besides one. The 1999 pinout on LT1swap.com for the C2 connector shows 12V+ switched power (Pink) need at PIN C4 for circuit 239 for "Fused Ignition Positive Voltage - Mass Airflow Sensor". On the 2005 pinout (which is the year of harness I have) there is no PIN at C4 and no circuit labeled 239. The only "Mass Airflow Sensor" type circuit I see is an additional wire at circuit 439 added to PIN B10 on my 2005 harness (PIN C11 on the 1999) that shows to be "Ignition 1 Voltage - MAF/IAT Sensor" Anyone else mod their own 2005 harness and can confirm the MAF power was moved from circuit 239 PIN C4 in 1999 to combine with circuit 439 PIN B10 in 2005?

I will add a links I am referring to from LT1swap.com for both 1999 and 2005.

1999:
http://www.lt1swap.com/vortec_truck_pinouts/1999.htm

2005:
http://www.lt1swap.com/vortec_truck_pinouts/2005.htm

Thanks in advance!

[BR3W CITY]

Well I know GM changed the design to combine the MAF/IAT into one unit in 2000 or 2001. Never combined them myself , although there are threads on ls1tech about doing the reverse....seperating them to run the IAT separately allowing for an SD tune. Maybe those may offer some insight?

[ls1nova71]

On a 2005, pin B10 is definitely for the MAF and IAT. I'm kind of at a loss as to why if you have a 2005, you're looking at pin outs for a 1999? Human nature I guess to complicate the simple, but I see it all the time. Not trying to pick on you, but rather trying to say don't overthink things.

[dropd80s]

Originally Posted by ls1nova71

On a 2005, pin B10 is definitely for the MAF and IAT. I'm kind of at a loss as to why if you have a 2005, you're looking at pin outs for a 1999? Human nature I guess to complicate the simple, but I see it all the time. Not trying to pick on you, but rather trying to say don't overthink things.

Lt1swap.com only lists which circuits will need power by pin on the 1999 pinout. The site suggested that you compare circuit #s for later years to compare what circuits moved to what pin etc. Since there is no 239 circuit on my 05 harness I am trying to verify where this circuit moved to to ensure I have power for it. With that being said the truck will more than likely be tuned using SD so it may be a mute point.... Either way I need to find out a definite answer of what needs power or removed. I will do some research on ls1tech
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[ls1nova71]

Originally Posted by dropd80s

Lt1swap.com only lists which circuits will need power by pin on the 1999 pinout. The site suggested that you compare circuit #s for later years to compare what circuits moved to what pin etc. Since there is no 239 circuit on my 05 harness I am trying to verify where this circuit moved to to ensure I have power for it. With that being said the truck will more than likely be tuned using SD so it may be a mute point.... Either way I need to find out a definite answer of what needs power or removed. I will do some research on ls1tech
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Ok. So what specifically are you researching for? Basically the pinks are the ignition wires. If you have a digital volt/ohm meter, you can do a continuity test on the pink wires if you're not sure what they go to.

[ls1nova71]

Originally Posted by BR3W CITY

Well I know GM changed the design to combine the MAF/IAT into one unit in 2000 or 2001.

Trucks since 1999 have had the IAT made into the MAF, 4th gen F-bodys use a seperate MAF and IAT. Just a fyi.

[rmvlt1100]

Originally Posted by dropd80s

I’m going through and getting my harness ready for the standalone conversion and have one question so far. I have found all necessary truck side connections that need to be made besides one. The 1999 pinout on LT1swap.com for the C2 connector shows 12V+ switched power (Pink) need at PIN C4 for circuit 239 for "Fused Ignition Positive Voltage - Mass Airflow Sensor". On the 2005 pinout (which is the year of harness I have) there is no PIN at C4 and no circuit labeled 239. The only "Mass Airflow Sensor" type circuit I see is an additional wire at circuit 439 added to PIN B10 on my 2005 harness (PIN C11 on the 1999) that shows to be "Ignition 1 Voltage - MAF/IAT Sensor" Anyone else mod their own 2005 harness and can confirm the MAF power was moved from circuit 239 PIN C4 in 1999 to combine with circuit 439 PIN B10 in 2005?

I will add a links I am referring to from LT1swap.com for both 1999 and 2005.

1999:
http://www.lt1swap.com/vortec_truck_pinouts/1999.htm

2005:
http://www.lt1swap.com/vortec_truck_pinouts/2005.htm

Thanks in advance!

My conversion I used a 2005 wiring harness. These wires all need some kind of power. You should have a 5 pin MAF for harness. There should be a yellow, lt. green possibly a tan along with a black and a pink. If you trace the pink back from the connector it should go to that under hood connector. When I did mine I cut all the pink and orange wires from the C-2 underhood harness. Then eliminated the others thta were not needed.
You are on the right track getting the conversion done. I also used the LT1swap info and there may have been a couple of differences in the wires, all I did was to trace the wires from there connectors back to either the computer or the under hood connectors. Good luck with the project and if you have any other questions please ask.

[dropd80s]

Originally Posted by ls1nova71

Ok. So what specifically are you researching for? Basically the pinks are the ignition wires. If you have a digital volt/ohm meter, you can do a continuity test on the pink wires if you're not sure what they go to.

Just making sure I have power to all wires that need it.

Originally Posted by rmvlt1100

My conversion I used a 2005 wiring harness. These wires all need some kind of power. You should have a 5 pin MAF for harness. There should be a yellow, lt. green possibly a tan along with a black and a pink. If you trace the pink back from the connector it should go to that under hood connector. When I did mine I cut all the pink and orange wires from the C-2 underhood harness. Then eliminated the others thta were not needed.
You are on the right track getting the conversion done. I also used the LT1swap info and there may have been a couple of differences in the wires, all I did was to trace the wires from there connectors back to either the computer or the under hood connectors. Good luck with the project and if you have any other questions please ask.

Thanks for your help man. I understand what needs to be done; I just wanted to make sure I had a good understanding of what was what before I jumped in. I like to understand what i'm doing as I'm doing it and why, as opposed to cut all this out, tie all these together, just because it says to do so. I started moding my harness last night and think I have everything removed and all wires from the PCM that need to be connected (TCC, ALT, etc.) labeled and pulled back. All I have left is labeling what pink wires are which at the C2 connector, and start routing everything back up the harness to go inside the truck.

I’m still trying to decide if I want to move the computer inside the truck or not. I think I’m going to try and lay the harness back on the motor and see how much effort it's going to take to get the branch of the harness for the PCM to exit toward the rear of the intake. To me, that huge harness hanging out of the driver side of the engine cover looks horrible on anything other than a completely stock looking install.

[shearjs]

Originally Posted by dropd80s

Just making sure I have power to all wires that need it.



Thanks for your help man. I understand what needs to be done; I just wanted to make sure I had a good understanding of what was what before I jumped in. I like to understand what i'm doing as I'm doing it and why, as opposed to cut all this out, tie all these together, just because it says to do so. I started moding my harness last night and think I have everything removed and all wires from the PCM that need to be connected (TCC, ALT, etc.) labeled and pulled back. All I have left is labeling what pink wires are which at the C2 connector, and start routing everything back up the harness to go inside the truck.

I’m still trying to decide if I want to move the computer inside the truck or not. I think I’m going to try and lay the harness back on the motor and see how much effort it's going to take to get the branch of the harness for the PCM to exit toward the rear of the intake. To me, that huge harness hanging out of the driver side of the engine cover looks horrible on anything other than a completely stock looking install.

Had I written my thoughts down as I were working through this, I think they'd be exactly the same as yours. I have my harness ready to lay on the engine and give it a test fire ( hopefully this wkend), so it's still to be determined if all is good or not. My plan is to put my computer inside the cab, as you're thinking. What I did to accomplish this look is, repinning the injectors on the driver side. I swapped the pins, where they attach to the computer, for Injector 1 to injector 7, and the pins for injector 3 to injector 5. The wire colors will now be different, but I don't see any reason it shouldn't work, at least in my head. Hopefully I'll find out for sure on Saturday, and report back. Good luck!

[rmvlt1100]

Originally Posted by dropd80s

Just making sure I have power to all wires that need it.



Thanks for your help man. I understand what needs to be done; I just wanted to make sure I had a good understanding of what was what before I jumped in. I like to understand what i'm doing as I'm doing it and why, as opposed to cut all this out, tie all these together, just because it says to do so. I started moding my harness last night and think I have everything removed and all wires from the PCM that need to be connected (TCC, ALT, etc.) labeled and pulled back. All I have left is labeling what pink wires are which at the C2 connector, and start routing everything back up the harness to go inside the truck.

I’m still trying to decide if I want to move the computer inside the truck or not. I think I’m going to try and lay the harness back on the motor and see how much effort it's going to take to get the branch of the harness for the PCM to exit toward the rear of the intake. To me, that huge harness hanging out of the driver side of the engine cover looks horrible on anything other than a completely stock looking install.

I mounted mine inside under the dash on the passenger side.




I kind of wish I would have ran the wires lower and came out behind the intake, but its done now and don't feel like filling the hole and drilling a new one. I used an existing hole just made it bigger.



It looks better with the wires wrapped in loom. I used stuff called tech flex.
I only had to add onto a couple of wires.

Have a good night.
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