6000 V6-173 2.8L VIN W FI (1986)
A/C Pressure Sensor/Switch - Cooling Fan: Technical Service Bulletins
Coolant Fan - Correct A/C High Pressure Switch Operation
Number 86-8-21
Date 11/86
Subject:
COOLANT FAN SYSTEM DIAGNOSTICS
1986 6000 MODELS EQUIPPED WITH LB6 ENGINE (2.8L V6 MFI VIN W)
COOLANT FAN SYSTEM
The 1986 6000 Service Manual may lead to unnecessary replacement of the air condition high pressure switch or electronic control module (ECM) as a
result of inaccurate information on the coolant fan control system used in the LB6 2.8L V6 MFI engine (VIN W).
When diagnosing a customer comment of cooling fan running whenever ignition switch is in run, please note the A/C high pressure switch is a normally
CLOSED switch. The 1986 6000 Service Manual incorrectly indicates that the A/C high pressure switch is a normally open switch.