12v switched – (single pink wire), Ls1_crank_sensor, Switched_ignition – Precision Turbo and Engine BigStuff3 GEN3 PRO SEFI (LS1) System Hardware & BigComm Software User Manual
Page 12
BigStuff3 Pro SEFI System (LS1)
Version 1.0
11
Fan Control (engine cooling fan) – (Single lead Packard connector with a single red wire)
This termination must go to the negative side of a fan relay, not directly to the fan.
Terminating this connection directly to a fan
will damage the BigStuff controller and will
void the warranty!
The fan connector is identical to the fuel pump connectors; so make sure
the label is read to ensure the connector is terminated correctly. Contact your BigStuff system
dealers for a relay and/or further details.
LS1 Crank Sensor (Black 3-way Packard Connector)
Connect to stock LS1 crank sensor, located on the passenger side of the engine, by the starter
motor.
Note: The LS1 Cam, Crank and MAP sensors use the same 3-way Packard connector,
therefore be sure to connect each of the 3-way connectors to the appropriate sensor!!
12V Switched – (Single pink wire)
A secure connection must be made to a switched 12V supply. The best and in most cases the
only source of a switched 12V supply is at the vehicle fuse block. The ECU must have a “live”
12V supply during cranking. If the 12V supply does
not stay live, during cranking, the ECU will not
function. A simple way to determine if a live 12V
supply exists during cranking is to check it with an
inexpensive voltmeter. Securely fasten the voltmeter’s
red (+ positive) wire to the ignition input on the fuse block. Secure the voltmeter’s black wire (-
negative) to a ground location on the fuse block or another adequate location. Once the
voltmeter connections are made, crank the engine. The voltage meter should indicate an output
voltage of between 8V to 14 volts. If the output voltage is below 8 volts, check to make sure the
battery is fully charged and all the cells of the battery are functioning properly.