I have a 99 grand cherokee. the radiator(aux.) fan will not come on. the temperature absolutely skyrockets if not moving. I have replaced the motor and was told my temp. sensor was fine. I was also told to change out the relay, but i have no idea where it is. does anyone know of the relay switch location or have a diagram that could be of some help. Is this even something i should be looking for. I've only had a jeep for a year and a half and am pretty stupid with them. Please help.

The electric fan relay on a 99 JGC is behind the front bumper under the passanger headlamp. Hard to see without removing the battery and box, but if you look under the headlamp area on the pass side you will see a small 1/2" high square with wires running to it. I removed the headlamp assembly and drilled 2 half inch holes over the top of the bolts and replaced it, If the fan doesnt work with the A/C then the relay is probably bad and fdrepairshop on this list has the part for less than the dealer or parts store. Easy fix but hard to get to. Good Luck

i think i have the same problems, my issue is the car is fine if it is moving, temperature and ac work ok. But when i'm at stop and go traffic or not moving it gets hot and the a/c does not blow cold air. If i understand correctly the a/c sensor and the engine temp sensor signals this relay fan that you are talking about and then the relay starts the fan. right?
So removing the head light is the easiest way to get to that relay?
man, this seems like it's my solution... well i'll look for that relay... tnaks for the info richpinkham you tha man!! wish me luck!!

I have the samr problem with my 99 overheating i have changed the temp sensor the fan relay and still my fan wont turn on i have to run it direct with a switch so it can work is there any answers to what might this be bad wiring? or What i am pretty fustrated with this i already spent money on a new fan new relay and new temp sensor anything else i should buy?thanks

Hi Ray. Did you ever get a resolution? I have the exact same problem on my 2003 and I also rigged a switch until I find a fix to the problem. Thanks.