03 silverado 4.3 to LS1 swap question
01-13-2016, 09:06 PM
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03 silverado 4.3 to LS1 swap question long story short:
heads/cam LS1/TH400 from '00 Camaro being put in a 2003 silverado that was originally a 4.3/auto truck....got a blue/green connector V8 truck harness that i was told was from a 2003 but the wiring in the C2 fuse block connector more closely matches a 2005...problem i have is in that C2 connector, pins A8, D5, and F10 are empty....not cut or removed, just weren't ever there. For some reason, i cannot find a diagram for a '03 4.3 silverado engine harness to see if that matters. the 3 missing wires are 2 battery(+) and one ignition voltage wire in the V8 harness but i dont know where they went to or what the corresponding pins in the 4.3 fuse box are.
I know for a typical 4.3 to 5.3 swap, you just get the matching year V8 harness and its plug-n-play. The LS1 isn't anything different, just a few different locations on some sensors but the harness & ecm don't know the difference once it's all plugged in. that's my main question i suppose, is what i have plug and play or do i need to repin the fuse block connector?
I already have added the appropriate pins and pigtails for the drive by cable throttle body and i do the tuning myself as well, i'm only concerned with the wiring at this point.
Thanks.
heads/cam LS1/TH400 from '00 Camaro being put in a 2003 silverado that was originally a 4.3/auto truck....got a blue/green connector V8 truck harness that i was told was from a 2003 but the wiring in the C2 fuse block connector more closely matches a 2005...problem i have is in that C2 connector, pins A8, D5, and F10 are empty....not cut or removed, just weren't ever there. For some reason, i cannot find a diagram for a '03 4.3 silverado engine harness to see if that matters. the 3 missing wires are 2 battery(+) and one ignition voltage wire in the V8 harness but i dont know where they went to or what the corresponding pins in the 4.3 fuse box are.
I know for a typical 4.3 to 5.3 swap, you just get the matching year V8 harness and its plug-n-play. The LS1 isn't anything different, just a few different locations on some sensors but the harness & ecm don't know the difference once it's all plugged in. that's my main question i suppose, is what i have plug and play or do i need to repin the fuse block connector?
I already have added the appropriate pins and pigtails for the drive by cable throttle body and i do the tuning myself as well, i'm only concerned with the wiring at this point.
Thanks.
01-15-2016, 06:54 AM
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I did this on a 2000 Silverado but used a 1999 5.3 harness, so both drive by cable. Everything just plugged in on my truck and worked fine. Did the 2003 4.3 truck come with a cable or wire throttle body?
01-15-2016, 09:05 AM
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That's where I determined the harness I had was from a 05, as it closely matches the wiring on the C2 connector, except I'm missing the wires i mentioned....just want to know where they go to in case I do need to add them
01-22-2016, 08:04 PM
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ok just an update....
the harness is in fact plug-n-play, as i suspected. The wiring diagram i was looking at was confusing because it showed all possible pins for a given year/model. The wires i was looking for were unnecessary as they only apply to hybrid trucks and i think 4 wheel drive applications if i recall...just updating the thread in case someone else needs it.
the harness is in fact plug-n-play, as i suspected. The wiring diagram i was looking at was confusing because it showed all possible pins for a given year/model. The wires i was looking for were unnecessary as they only apply to hybrid trucks and i think 4 wheel drive applications if i recall...just updating the thread in case someone else needs it.