T56 Wiring for Chevelle LS3 376/480 Swap
01-02-2012, 01:36 PM
#1
Staging Lane
Thread Starter
iTrader: (2)
Join Date: Nov 2005
Location: Belleville, Il
Posts: 87
Likes: 0
Received 0 Likes
on
0 Posts
T56 Wiring for Chevelle LS3 376/480 Swap First off - I am more mechanically inclined, so this wiring is a learning process for me. I did a quick search of the existing threads and a few stickies, and came up empty handed.
What I have is a 1972 Chevelle that has a GM Crate LS376/480 installed, and matched to a T56 that was rescued from a 1999 WS6. I have the factory engine installation harness (PN 19201792), that has provisions for VSS input (with a fitting and all) - but the instructions state that "VSS is not required for proper engine operation, but is available on the majority of late model automatic transmissions". What I have been able to gather is that it is also available on my T56. However - so is the backup light switch, skip shift solenoid, and reverse lockout (I still have the reverse lockout solenoid installed).
Simple question - since my factory harness does not control these items (but does accept input from the VSS) - where can I get a harness (just for the tranny) that does? And then - how would I tie that in with the engine harness - or is that even necessary aside from the VSS?
Specifics:
Car: 1972 Chevelle
Engine: LS376/480
Harness: GM 19201792
Tranny: 1999 WS6 T56
Tranny harness: None
WS6 rear gears: 3:42
Chevelle rear gears: 3:90
What I have is a 1972 Chevelle that has a GM Crate LS376/480 installed, and matched to a T56 that was rescued from a 1999 WS6. I have the factory engine installation harness (PN 19201792), that has provisions for VSS input (with a fitting and all) - but the instructions state that "VSS is not required for proper engine operation, but is available on the majority of late model automatic transmissions". What I have been able to gather is that it is also available on my T56. However - so is the backup light switch, skip shift solenoid, and reverse lockout (I still have the reverse lockout solenoid installed).
Simple question - since my factory harness does not control these items (but does accept input from the VSS) - where can I get a harness (just for the tranny) that does? And then - how would I tie that in with the engine harness - or is that even necessary aside from the VSS?
Specifics:
Car: 1972 Chevelle
Engine: LS376/480
Harness: GM 19201792
Tranny: 1999 WS6 T56
Tranny harness: None
WS6 rear gears: 3:42
Chevelle rear gears: 3:90
01-11-2012, 10:21 PM
#3
Staging Lane
Thread Starter
iTrader: (2)
Join Date: Nov 2005
Location: Belleville, Il
Posts: 87
Likes: 0
Received 0 Likes
on
0 Posts
Okay, one more bump.
I have found that American Autowire sells the T56 pigtails, so I can just make my own harness if need be. Does anyone know where I can get a stand alone harness or where I route the wires for proper Tranny operation? BTW - the harness I have for the LS3 does not control the T56 - I need something else.
TJR
I have found that American Autowire sells the T56 pigtails, so I can just make my own harness if need be. Does anyone know where I can get a stand alone harness or where I route the wires for proper Tranny operation? BTW - the harness I have for the LS3 does not control the T56 - I need something else.
TJR
01-12-2012, 12:00 PM
#4
i would get the appropriate pigtails to make my own and run the inputs for the lockout solenoid and VSS to the proper ECM input. The backup light switch wiring can can ran to a relay for the backup lights then to the lights themselves. I would leave the skip shift circuit disabled.
01-12-2012, 12:34 PM
#5
You have the GMPP kit for the LS376/480?
From what I can find (since I am doing the same), the controller is already programmed to activate the reverse lockout solenoid when the VSS indicates under 5 mph. Like you mentioned, the harness has a VSS connection. It's not needed for the engine, but is for the reverse lockout, and automatic trans shifting, & speedo if connected through the computer. I haven't looked, don't know if it is the proper connection to mate with the T56. Your T56 has a VSS connection on it. Reverse switch is not needed in the engine harness, just wire that in place of the PRNDL reverse circuit. Pin on the E67 computer for the reverse lockout is connector 3, pin 8.
From what I can find (since I am doing the same), the controller is already programmed to activate the reverse lockout solenoid when the VSS indicates under 5 mph. Like you mentioned, the harness has a VSS connection. It's not needed for the engine, but is for the reverse lockout, and automatic trans shifting, & speedo if connected through the computer. I haven't looked, don't know if it is the proper connection to mate with the T56. Your T56 has a VSS connection on it. Reverse switch is not needed in the engine harness, just wire that in place of the PRNDL reverse circuit. Pin on the E67 computer for the reverse lockout is connector 3, pin 8.
08-09-2012, 03:59 AM
#6
Staging Lane
Thread Starter
iTrader: (2)
Join Date: Nov 2005
Location: Belleville, Il
Posts: 87
Likes: 0
Received 0 Likes
on
0 Posts
I know I am kind of digging up bones here, but the guy I had lined up to help wire the car backed out of the deal, so I am getting more serious about doing it myself. Just wondering if you tried this, and if it worked? I think I can run the VSS lead TO the ECM, then feed the Speedo off the VSS lead FROM the ECM. Then run the reverse lockout to the pin indicated above - assuming this really works.
Thoughts?
TJR
Thoughts?
TJR
