I have a 98 disco with the v8 has 137k miles and runs like a dream never has over heated on me but I’ve only had it for this winter but I took it wheeling this weekend and on the up hill it started to overheat a tick over middle and no cooling fans came on even when it was shut off but when I turned on the ac they kicked on so that means the fuses and relays are working. I do know they turn on from the ecu but mine arnt for some reason, this has also happened when towing up hill if any one knows any trouble shoots please let me know it whould be gratefully appreciated.