Illustration 64. This schematic represents the on/off fan

206

TM 9-2320-312-24-2

Troubleshooting Section

normally open with a pneumatic air solenoid

normally closed with a pneumatic air solenoid

normally open with an electrically controlled

solenoid

normally closed with an electrically controlled

solenoid

The following OEM installed components may

affect the operation of the cooling fan in some

applications:

OEM installed, normally open relay

The a/c high pressure switch is connected to

the ECM or the a/c high pressure switch is

independent of the ECM.

Cab mounted manual override switch

A timer that keeps the fan in the ON position

Cooling fan air solenoid valve

g00766507

Illustration 64

This schematic represents the on/off fan with a direct solenoid connection to the ECM and the A/C pressure switch connected to the ECM input.