Cooling System - Fan Runs With Ignition Switch Off
Group Ref.: EngineBulletin No.: 316201
Date: November, 1993
SUBJECT:
COOLING FANS RUN WITH IGNITION OFF
(REPLACE FAN MOTOR/REPLACE FAN RELAYS/INSTALL DIODE)
MODELS:
1993 CADILLAC FLEETWOOD AND FLEETWOOD BROUGHAMS (EQUIPPED WITH ELECTRIC COOLING FANS)
Some owners may experience an intermittent condition of fan(s) continuing to run after ignition off. This condition may be caused by cooling fan relay(s) remaining in the energized position.
To diagnose and repair this condition perform the following procedure:
1. Measure the start up and steady state (fan running) current draw of the primary and secondary fan motors. Replace the fan motor if the current draw exceeds:
^ 70 amps at start up
^ 18 amps at steady state
2. Replace the cooling fan relay(s), P/N 12088572, for the fan(s) that remained running at ignition off.
3. Install diode, P/N 12112422, or equivalent (3 amps/400 volts diode) at each fan motor connector. Refer to Figure 1.
Parts are currently available from GMSPO.
For warranty purposes use:
Labor Operation:
N2850 to install cooling fan relay
N6270 to install diode
J3400 to replace secondary fan motor
J3401 to replace primary fan motor
J3407 to replace both fan motors