Official NBS V6 to GENIII V8 swap Guide
12-01-2018, 11:05 PM
#272
Hey everybody it’s me again and I have another question on my swap. So I’m switching harnesses from an 03-07 to a 99-02 harness ( because my truck is a 2002) but anyways my question is this: are the injector plugs different on an 03-07 motor than what they are on a 99-02 motor? If so, is it best that I try to get the harness with the injectors? Or will I be able to cut the plugs from the 03-07 harness and solder them to my 99-02 harness? Thanks in advance!
12-03-2018, 06:21 AM
#273
If you are going from V6 to V8 then you will need whatever underhood harness from the V8 also because otherwise you will be missing the plug for the other 2 injectors. that was the case for me - but if you are going V8 to V8 - that I don't know.
12-04-2018, 02:23 AM
#274
100% Redneck
Hey everybody it’s me again and I have another question on my swap. So I’m switching harnesses from an 03-07 to a 99-02 harness ( because my truck is a 2002) but anyways my question is this: are the injector plugs different on an 03-07 motor than what they are on a 99-02 motor? If so, is it best that I try to get the harness with the injectors? Or will I be able to cut the plugs from the 03-07 harness and solder them to my 99-02 harness? Thanks in advance!
12-04-2018, 08:06 PM
#275
Hello once more everyone, so I have run into a number of problems between my harness and my engine. So I’m trying to install a v8 99-02 harness on an engine and transmission, the engine and tranny i am trying to put the harness on is from a 2004 5.3 Tahoe. When I got my 99-02 harness it had sensor plugs missing. The 2004 Tahoe engine had a complete harness with the sensors and everything. What I’ve been doing is taking the missing plugs from the tahoe harness, and re-soldering them onto the 99-02 harness. But I’ve run into some problems. I’ve noticed that some of the sensors are different on the engine than they are on the 99-02 harness such as: the oil pressure sensor plug from the 99-02 harness has only one wire while the Tahoe engine has 3 wires. Also, the neutral safety switch is one giant connection, but on the 99-02 harness it appears to be two different plugs. Can anybody out there confirm if the 99-02 harness is compatible with the Tahoe engine? Is there any way I can still use the harness and not have to spend any more money? I really need some help with this because I am very confused and i don’t have much more cash to spend on my project.
12-05-2018, 09:02 AM
#276
100% Redneck
Hello once more everyone, so I have run into a number of problems between my harness and my engine. So I’m trying to install a v8 99-02 harness on an engine and transmission, the engine and tranny i am trying to put the harness on is from a 2004 5.3 Tahoe. When I got my 99-02 harness it had sensor plugs missing. The 2004 Tahoe engine had a complete harness with the sensors and everything. What I’ve been doing is taking the missing plugs from the tahoe harness, and re-soldering them onto the 99-02 harness. But I’ve run into some problems. I’ve noticed that some of the sensors are different on the engine than they are on the 99-02 harness such as: the oil pressure sensor plug from the 99-02 harness has only one wire while the Tahoe engine has 3 wires. Also, the neutral safety switch is one giant connection, but on the 99-02 harness it appears to be two different plugs. Can anybody out there confirm if the 99-02 harness is compatible with the Tahoe engine? Is there any way I can still use the harness and not have to spend any more money? I really need some help with this because I am very confused and i don’t have much more cash to spend on my project.
The 99-02 high pressure switch for the A/C compressor may be an issue because some of the 03+ compressors did not have the high pressure switch in that location. If your compressor has the purple connector on the rear of the compressor you're golden... if not you can deal with that issue when the season changes.
What connectors is missing from the 99-02 harness besides the oil pressure sending unit? As you know the oil sending units are different between the 99-02 and the 03+. You'll need the one wire oil sending unit from an 99-02 and the correct pigtail to solder on the 99-02 harness. The pigtail part number is "WELLS 1P1054" it's $11 shipped from Amazon. The one wire sending unit will hurt you at around $45 if I recall correctly (I had an 05 engine going in a 00 so I had to buy the single wire sensor) unless you have a used one laying around.
To find any other connectors for the 99-02 harness that have been cut go to RockAuto.com
Rock Auto > Chevrolet > 2002 > Silverado 1500 > 5.3 > Electrical Connector (scroll to what you're looking for) then you can copy the part numbers needed and compare prices over at Amazon.
vv CLICK BELOW vv
Rock Auto > 2002 > Chavrolet > 5.3 > Electrical Connector
Use these photos for reference it will help sorting out the connectors
Last edited by RedXray; 12-05-2018 at 09:17 AM.
12-05-2018, 05:23 PM
#277
The 03+ Tahoe engine itself will connect to the 99-00 harness. The differences between the two are the throttle body sensors and the oil pressure sensor. Are you running a cable type throttle body... if so the 99-00 harness is plug & play.
The 99-02 high pressure switch for the A/C compressor may be an issue because some of the 03+ compressors did not have the high pressure switch in that location. If your compressor has the purple connector on the rear of the compressor you're golden... if not you can deal with that issue when the season changes.
What connectors is missing from the 99-02 harness besides the oil pressure sending unit? As you know the oil sending units are different between the 99-02 and the 03+. You'll need the one wire oil sending unit from an 99-02 and the correct pigtail to solder on the 99-02 harness. The pigtail part number is "WELLS 1P1054" it's $11 shipped from Amazon. The one wire sending unit will hurt you at around $45 if I recall correctly (I had an 05 engine going in a 00 so I had to buy the single wire sensor) unless you have a used one laying around.
To find any other connectors for the 99-02 harness that have been cut go to RockAuto.com
Rock Auto > Chevrolet > 2002 > Silverado 1500 > 5.3 > Electrical Connector (scroll to what you're looking for) then you can copy the part numbers needed and compare prices over at Amazon.
vv CLICK BELOW vv
Rock Auto > 2002 > Chavrolet > 5.3 > Electrical Connector
Use these photos for reference it will help sorting out the connectors
The 99-02 high pressure switch for the A/C compressor may be an issue because some of the 03+ compressors did not have the high pressure switch in that location. If your compressor has the purple connector on the rear of the compressor you're golden... if not you can deal with that issue when the season changes.
What connectors is missing from the 99-02 harness besides the oil pressure sending unit? As you know the oil sending units are different between the 99-02 and the 03+. You'll need the one wire oil sending unit from an 99-02 and the correct pigtail to solder on the 99-02 harness. The pigtail part number is "WELLS 1P1054" it's $11 shipped from Amazon. The one wire sending unit will hurt you at around $45 if I recall correctly (I had an 05 engine going in a 00 so I had to buy the single wire sensor) unless you have a used one laying around.
To find any other connectors for the 99-02 harness that have been cut go to RockAuto.com
Rock Auto > Chevrolet > 2002 > Silverado 1500 > 5.3 > Electrical Connector (scroll to what you're looking for) then you can copy the part numbers needed and compare prices over at Amazon.
vv CLICK BELOW vv
Rock Auto > 2002 > Chavrolet > 5.3 > Electrical Connector
Use these photos for reference it will help sorting out the connectors
12-06-2018, 01:58 AM
#278
100% Redneck
The transmission range PRNDL switches are not the same nor is the connector. The 03+ uses a single connector and the 99-02 uses a double connector. Both the 99-02 and the 03+ connectors have eleven wires... are the wires the same color? the pinouts the same at the PCM???? If so you maybe able to use the new connector but you'll have to purchase an 03+ neutral safety switch (PRNDL). If you still have the V6 harness you may be able to cut the PRNDL harness with switch and solder to the 99-02 harness. The factory glues the harness plugs to the PRNDL switch and they usually break when trying to separate the connectors. Some have had success with a heat gun, me, not so lucky, I had to buy a new PRNDL switch doing the swap.
The rear (downstream) o2 sensors are not necessary but will show a DTC code on the dash. The codes can easily be tuned out if the truck is professionally tuned. Is this a pure stock swap? headers? etc? Your state inspection may require the downstream o2's in place and operational, mine does not.
My recommendation is to find an uncut 99-02 harness from a 1500 series V8 Silverado, Sierra, Tahoe, Yukon, Escalade or Suburban that has the 4L60E. You can make the cut harness work if your budget forces but you may be causing yourself more work, headache and money. I sold my 05 PCM and harness then bought the correct 99-02 harness and PCM off e-bay.
You will not be able to use the (Blue/Green) 03+ PCM unless it has IAC (idle air control) drivers... some do some don't. Only way to tell is to open the computer. The easiest PCM to find is the 99-02 (Blue/Red) P01 (0411).
The rear (downstream) o2 sensors are not necessary but will show a DTC code on the dash. The codes can easily be tuned out if the truck is professionally tuned. Is this a pure stock swap? headers? etc? Your state inspection may require the downstream o2's in place and operational, mine does not.
My recommendation is to find an uncut 99-02 harness from a 1500 series V8 Silverado, Sierra, Tahoe, Yukon, Escalade or Suburban that has the 4L60E. You can make the cut harness work if your budget forces but you may be causing yourself more work, headache and money. I sold my 05 PCM and harness then bought the correct 99-02 harness and PCM off e-bay.
You will not be able to use the (Blue/Green) 03+ PCM unless it has IAC (idle air control) drivers... some do some don't. Only way to tell is to open the computer. The easiest PCM to find is the 99-02 (Blue/Red) P01 (0411).
12-06-2018, 05:43 PM
#279
The transmission range PRNDL switches are not the same nor is the connector. The 03+ uses a single connector and the 99-02 uses a double connector. Both the 99-02 and the 03+ connectors have eleven wires... are the wires the same color? the pinouts the same at the PCM???? If so you maybe able to use the new connector but you'll have to purchase an 03+ neutral safety switch (PRNDL). If you still have the V6 harness you may be able to cut the PRNDL harness with switch and solder to the 99-02 harness. The factory glues the harness plugs to the PRNDL switch and they usually break when trying to separate the connectors. Some have had success with a heat gun, me, not so lucky, I had to buy a new PRNDL switch doing the swap.
The rear (downstream) o2 sensors are not necessary but will show a DTC code on the dash. The codes can easily be tuned out if the truck is professionally tuned. Is this a pure stock swap? headers? etc? Your state inspection may require the downstream o2's in place and operational, mine does not.
My recommendation is to find an uncut 99-02 harness from a 1500 series V8 Silverado, Sierra, Tahoe, Yukon, Escalade or Suburban that has the 4L60E. You can make the cut harness work if your budget forces but you may be causing yourself more work, headache and money. I sold my 05 PCM and harness then bought the correct 99-02 harness and PCM off e-bay.
You will not be able to use the (Blue/Green) 03+ PCM unless it has IAC (idle air control) drivers... some do some don't. Only way to tell is to open the computer. The easiest PCM to find is the 99-02 (Blue/Red) P01 (0411).
The rear (downstream) o2 sensors are not necessary but will show a DTC code on the dash. The codes can easily be tuned out if the truck is professionally tuned. Is this a pure stock swap? headers? etc? Your state inspection may require the downstream o2's in place and operational, mine does not.
My recommendation is to find an uncut 99-02 harness from a 1500 series V8 Silverado, Sierra, Tahoe, Yukon, Escalade or Suburban that has the 4L60E. You can make the cut harness work if your budget forces but you may be causing yourself more work, headache and money. I sold my 05 PCM and harness then bought the correct 99-02 harness and PCM off e-bay.
You will not be able to use the (Blue/Green) 03+ PCM unless it has IAC (idle air control) drivers... some do some don't. Only way to tell is to open the computer. The easiest PCM to find is the 99-02 (Blue/Red) P01 (0411).
12-14-2018, 12:23 AM
#280
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V6 to 5.3
My truck is a 2005 base work truck rcsb. V6 2wd auto. I'm about to buy a 05 5.3 out of a Suburban and it is a Flex fuel engine being the vin has "Z" in it. Will the wiring harness work? I've read this entire post but just to make things a little more simple and faster, could someone tell me what I'll need? Instead of going back and reading everything over and over lol. This is a great write up but I've noticed some things were not clarified when swapping. I'd appreciate it. Thanks