Chart C-12C-B

Chart C-12C-B:

Cooling Fan Circuit:

CIRCUIT DESCRIPTION:
This system uses the PCM, and three relays for control of two coolant fans.

Low Speed - The "LO" speed of both fans is controlled by the PCM. The PCM energizes coolant fan relay "G" through terminal "GC4" when either the coolant temperature exceeds 214°F (101°C) or A/C high side temperature exceeds 122°F (50°C).

High Speed - The high speed of both fans is controlled by the PCM. The PCM energizes all three relays, when either coolant temperature exceeds 226°F (108°C) or A/C high side refrigerant temperature exceeds 149°F (65°C).

TEST DESCRIPTION: Numbers below refer to circled numbers on the diagnostic chart.

1. Test light should be "ON" because harness terminal 5 has B+ with ignition switch turned "ON."

2. Test light "ON" validates circuit 536 from PCM to relay "C."

3. Jumpering 1 to 4 of relay "C" bypasses fan relay.

4. Test light "ON" validates all circuits. If light is "ON," rear fan motor is faulty. If light is "OFF," it is a problem with the ground CKT 804.