Some 2003 ls pcm s tach signal is not strong enough and needs boosted see this link.
Ls swap electric fan wiring.
Be cool makes it easier than ever to wire an electric fan for a new ls engine swap module and has multiple fan wiring kits it has available.
You can not directly connect pcm fan control wire to fans.
In this way the electric fan motors are wired in a series and voltage is reduced causing the fan motors to spin at low speed.
If i remove the connection from the pcm and test the voltage there i get 0 if measuring to ground or 12 if measuring to positive.
A relay kit our part number ccfkrl will include everything you need to properly wire up your electric cooling fans with the exception of additional wiring needed to complete all of the circuits.
Also included is an easy to follow wiring diagram.
Thank you to all that stuck with us during this hectic time.
The pcm will supply the negative or ground signal to turn on fan relays.
30 other red wire needs constant 12 volt power from the battery.
We are currently up and running and shipping from our new location.
Lt1 ls1 05 oem flex a lite universal street strip we have you covered.
You must use a relay.
87 red wire connects to the positive wire on the electric fan.
Your 1 source for oem operated pcm controled and universal electric fan harnesses.
The fan s are triggered via a temperature switch and 40 amp relay combination.
I am working on a ls swap and i cannot get the cooling fans to work.
A complete installation instruction booklet is included with every module.
Electric fan wiring for proper electric fan control when the a c is on the best pcm and calibration choice is 1999 2002 camaro firebird corvette.
In these vehicles the pcm receives a 12v request from the control head checks the refrigerant pressure activates the compressor clutch relay and monitors the voltage on the compressor clutch to.
It seems for many people that the scariest part of the modern engine swap is the wiring harness.
Fan controls 1 2 gm pcm s typically will control electric fans usually 2.
When i measure voltage at the relay i get 12v on both sides of the coil.
The first part of the installation is to install the electric fan to your radiator and remove the mechanical fan.
86 gray white wire goes to the ignition switch.
When you are doing a build with the ls family of gm engines the idea is to end up with a.
When the pcm triggers the two additional relays the same voltage flows through each electric fan motor.