Jeep Repair: 2004 Grand Cherokee Special Edition Overheat, 2004 jeep Grand cherokee fan relay

Question
I took my car in for overheating.  They replaced the t-stat and it was still overheating.  The were trying to locate the relay switch and could not find it.  This is a reliable shop and knew where they were typically (down close to the headlight).  They even called Chrysler and had a lead tech on the phone and still could not locate it.  Has anyone had this problem and what should I do?  The shop gave up because they spent 1.5 days with the entire bumper and front end off trying to find it.

Answer
You know for some reason jeep eliminated the FC relay for some models and now relies on the computer to determine when and at what speed the fan should run based on coolant temperature inputs and A/C compressor status. If the fan is not working properly i would consider replacing the fan, I will enclose an article from a guy that had your same problem and this is what he did to fix it Hope this helps you.


"I have a 04 GC also with the 4.0 and I could not find my FC relay either. Nobody at a local dealer here had ever heard of this phantom FC relay problem. I was able to find an electrical diagram on the web that does not show the FC relay for the 04 GC but that was it. The diagram only showed the PCM and two relays in the PDC near the battery. My GC was overheating now and then. It would seem to overheat when you were in stop and go traffic or letting it idle. I was not losing any coolant so I replaced the thermostat but that did not fix it. After much frustration I started the engine and sat there and watched it run until it began overheating. I paid particular attention to the fan. When the engine began to overheat the fan was barely spinning and would even shut off at times during the overheating. I knew this was not right so that is when I began this search for the FC relay but I could not find it. I disconnected the fan and did some checking on the two speed electric radiator fan. It has a 3 pin connector where the center pin is ground. When I ran power to one pin and grounded the center pin the fan would run. However when I switched the power to the other pin I got nothing. I had already checked operation of the Low and High Speed relays in the PDC near the battery and all checked out so I went and picked up a new radiator fan assembly and installed it. That was yesterday and that fixed the overheating problem. I have concluded that for some reason jeep eliminated the FC relay for some models and now relies on the computer to determine when and at what speed the fan should run based on coolant temperature inputs and A/C compressor status. I also found out that although my GC does not have the towing package it does have the max cooling package. When I went looking for a new motor for the radiator fan at local auto parts store I was asked if it had the towing package and I answered no. Everytime I did they would bring out a motor that only had a 2 pin connector. Not one of them kept the motor that would be needed if you had the towing package. I bet if they did it would have a 3 pin connector on it. So while my GC does not have the towing package I think it has the max cooling package that usually comes with the towing package. I think the standard cooling package uses a one speed fan where the max cooling package uses a two speed fan. It may be that the standard cooling package uses the FC relay which is supposed to be under the passenger headlight but the max cooling package eliminates the relay and uses the PCM to control two relays in the PDC which in turn run the fan. One more thing....replacing the radiator fan assembly involves removing the shroud. One of the 4 screws that holds the shroud is in a very tight space. I fianlly got to it with a long socket extension and swivel. I know this is long but I hope it helps because I was very frustrated at the lack of informartion available locally and on the web in reference to this oddity" (article found on web)