Chrysler Repair: 96 LHS Cooling fans, interference module, pin sockets

Question
Car overheats...so, I replaced the thermostat and ran the car...then I noticed that the radiator fans are not operating.  I checked the fan's fuse, bypassed the Temp sensor, swapped the 2 fan relays with other system relays using the same relays and now I am stumped.  Is there a computer or some other type of circuit board in the cooling system to activate the fans????

Answer
Hi Curtis,
I am not certain whether to use the '94 or the '98 wiring diagrams that I have for the LHS. If its like the 98 there will be 4 wires at the fan module, a light green, a tan, and two black wires. If it is like the 94 it will be yellow, tan, and one or two blacks. In either case, I would begin by trying to verify that you have good ground connection(s) for the black wires, at location which may be near the left head headlamp. Then I would try to directly power the fans by jumping to the other colored wires, one at a time and also grounding the black wires to the - post of the battery so as to complete the circuit:this is to verify that the fans are working. If you have the 94 type wiring, there is a radiofrequency interference module on the fan assembly which is between the incoming wires and the fan motors, and that module could be the problem. If that is the case, one of the motors will be a blue and black wired fan, and the other a brown, yellow and black wire to the motor. There would then be a plug right near each fan that you could disconnect to do the same jumper test (black is always the ground, the other color wires would be the ones to apply +12V to test the motor). So do those tests depending upon how you find the wires and let me know the results of whether the fans directly wires will run or not.
The relays are further upstream and there actuation is indeed mediated by the engine controller, but you can bypass that control by removing the relay and jumping across its pin sockets (which should be labelled B and D). If the fans will operate that way, then the problem is at the engine controller or the sensors that tell the engine controller to turn on the fans. The fans should always come on when you activate the defrost or the AC choices so that is another way to test the system to see if it may be an issue with the controller not sensing when the engine is running too hot.
I will await your feedback.
Roland