H20 – (black, 2-way packard connector), Air – (gray, 2-way packard connector), Coolant_temp – Precision Turbo and Engine BigStuff3 GEN3 PRO SEFI (LS1) System Hardware & BigComm Software User Manual
Page 14: Air_temp

BigStuff3 Pro SEFI System (LS1)
Version 1.0
13
H20 – (Black, 2-way Packard connector)
This connector mates with a GM style coolant temperature sensor (front driver’s side cylinder
head).
Air – (Gray, 2-way Packard connector)
This connector mates with a GM style air temperature sensor in the inlet duct between the air
cleaner and the throttle body.
IAC (Idle/Air Control) – (Black, 4-way Packard connector)
The main harness IAC connector was designed to work with a GM style IAC motor and valve
assembly with an in-line 1-by-4 connector.
Alternatively, the factory installed 1-by-4 in-line connector can be removed and replaced with a
2-by-2 connector per the pin-out table below.
LS1 In-line, 1-by-4, IAC
Connector Pin-out
IAC Coils
Late Model 2-by-2 IAC
Connector Pin-out
D
A-Hi
A
C
A-Lo
B
B
B-Hi
C
A
B-Lo
D
TPS (Throttle Position Sensor) – (Black, 3-way Packard connector)
Connect the TPS connector to the LS1 throttle
position sensor, located on the engine throttle
body.
Alternatively, the factory installed TPS
connector can be removed and replaced with a
late model GM or Ford TPS connector per the pin-out tables below.