Does your fan only works on high (speed 4)? Try changing the blower motor resistor.
Product details
Product type: Blower Resistance For Dodge, Jeep, Ram
OE No.: 68004539AA
Other numbers: 4720278,973-020,68004539AA,
5012212AA,RU109,RU876,68004241AA,3A1049,20116,CR153,1712032
Application
for Dodge Ram 1500 Truck Blower Motor Resistor 1994-06
for Dodge Ram 1500 Truck 2007-08
for Dodge Ram 2500 Truck 2007-09
for Dodge Ram 2500 Truck Blower Motor Resistor 1994-06
for Dodge Ram 3500 Truck 2007-09
for Dodge Ram 3500 Truck Blower Motor Resistor 1994-06
for Jeep Grand Cherokee 1997-99
for Jeep Grand Cherokee Blower Motor Resistor 1993-96
Package Content: 1 x Heater Blower Fan Resistor