Wiring for Dummies -101 ... Need advice !!

[Richard]

Originally Posted by Accelo

Two speed fans.
Both fans run either at slow speed or both at high speed.
Incorporates two fans and uses three relays.
Used in conjunction with aftermarket air.
Assumes the ECM has a high and low temperature outputs from the computer.
This setup is not for PCM setups. (pulse width modulated)
Does quiet the fans when only low speed it required.
Air Conditioning ON is connected to the HS ground and runs both at high speed.
Cheers

Odd to me that high speed is commanded with A/C call. FWIU an A/C call from a stock ecm or aftemarket pwm controller is only 50% to the fan/fans. Also with the pressure sensor installed fans will shut off at speed if they are not needed. Obviously if the motor needs cooling higher speed call will always take preference. Problems arise mostly with two fans and only operating one at a time. Recirculation of engine compartment air through the unpowered fan reduces efficiency.