Chrysler Repair: cooling fans, amp fuse, amp fuses

Question
I have a 95 Dodge Intrepid. The cooling fans do not turn on. I have hot wired them and they both work perfectly well. I have also changed the temp sensor and checked the relays and 40 amp fuse. Got any ideas?

Answer
Hi Bill,
I am working with the '94 manual for the LH body cars that includes the Intrepid. I have a few suggestions.
First, while you have replaced the coolant sensor and the checked the relays and the fans, it will probably be helpful to have a volt-ohmmeter or 12v neon glow light to check for the actual presence of voltage. I wonder if when you turn on the AC do the fans start up? They should if the circuit for the fan actuation was working because the coolant temp sensor is by-passed when the AC is activated.
Then you said that you checked the 40 amp fuse. My diagrams show there to be two 40 amp fuses in positions J and C and neither of those are feeding the fans! The fans fuse is a 20 amp fuse in position D (inboard row of 5, next to the frontmost fuse). So check that fuse instead which if not patent would explain why your fans won't work.
So then check whether you have 12V on the pin for each of the fan relays that is closest to the front of the vehicle which is where the feed from fuse D is sent. If you have that, and the relays are good, and you have 12V on the fan relay socket pins that are on the outboard side when the ignition switch is "on" (if not check 10 amp fuse #20 in the junction block under the dash for the voltage that supplies the relay actuation coils), the the engine controller should turn on the fans by gounding the other end of the coils of the relays. Notice that the fans are not directly connected to the relay outputs but that there is a radiofrequency interference module mounted in the lower middle of the fan assembly. That module may be burned out which would then explain why the fans will work if jumped directly but not when wired normally. So I would check to see if you are getting 12v on the tan and the yellow wires that come into that module from the relays when you have the AC activated or the engine is hot, and if you do, yet the fans don't run, then I believe that would prove that the rfi module is bad.
So those are some ideas to check out.
Please let me know what you find out.
Roland