The engine cooling fan system is composed of one cooling fan, a series of 5 relays, the engine control module (ECM), and the associated wiring. The cooling fan assembly includes two resistors. This combination of components enables the ECM to operate the cooling fan at 3 speeds using two fan control circuits.
Low Speed Operation
The ECM applies ground at the FAN 1 control circuit for the coil side of the cooling fan relay. The energized cooling fan relay completes a ground, through the switch side of the relay, for the coils of the cooling fan low speed relay and the cooling fan speed control relay. The speed control relay activates and supplies B+ to the coil side of the cooling fan high speed relay. The high speed relay remains inactive because the ECM is not commanding the FAN 2 control circuit ON. The energized low speed relay switch closes to supply B+ through the internal low speed resistor of the engine cooling fan motor. The result is cooling fan operation at a reduced speed.
Medium Speed Operation
The ECM applies ground at the FAN 2 control circuit for the coil side of the cooling fan high speed, and medium speed relays. The high speed relay remains inactive because the ECM is not commanding the FAN 1 control circuit ON. The energized medium speed relay switch closes to supply B+ through the internal medium speed resistor of the engine cooling fan motor. The result is cooling fan operation at a medium speed.
High Speed Operation
The ECM applies ground at the FAN 1 control circuit for the coil side of the cooling fan relay. The energized cooling fan relay completes a ground, through the switch side of the relay, for the coil of the cooling fan speed control relay. The energized speed control relay switch closes to supply B+ to the coil side of cooling fan high speed relay. Simultaneously, the ECM applies ground at the FAN 2 control circuit for the coil side of the cooling fan high speed relay. The energized high speed relay switch closes to supply B+ directly to the engine cooling fan motor, by-passing the fans internal resistors. The result is cooling fan operation at full speed.
Hood Rear Seal Replacement
Hood Rear Seal Replacement
Callout
Component Name
1
Hood Rear Seal
Procedure
Clean the area where the seal will be mounted. Use a suitable solvent
with a mixture of 50?€‰percent isopropyl alcohol and 50?â ...
Park Brake System Description and Operation
System Component Description
The park brake system consists of the following:
Park Brake Lever Assembly
Receives, multiplies, and transfers park brake system apply input force
from driver to park brake cable system.
Releases applied park brake system when lever release ...
Transmission Component and System Description
The mechanical components of the 6T30/40/45/50 are as follows:
A torque converter with an electronically controlled capacity clutch (ECCC)
Gear-type fluid pump assembly
1??? and low and reverse clutch housing assembly
4?? and 3? reverse clutch housing assembly
2? clutch assem ...