Initial Inspection and Diagnostic Overview

If it is suspected that the cooling fan controller is not operating properly, diagnosis of the controller can be performed by back-probing the controller connection, with the connection plugged into the controller, and taking voltage measurements. The readings should be made during the following three tests:

^ Test 1: Ignition switch in off.

^ Test 2: Ignition switch in run, engine off, A/C off.

^ Test 3: Ignition switch in run, engine running, and A/C on.

The readings should be obtained at the indicated connector pins. If the indicated voltage is not present, refer to the system diagrams for further diagnosis.