I have the long standing issue of temperature gauge going into the red while motorway driving that is well documented on this forum. I have tried just about every suggestion mentioned to rectify the fault, so now trying to come up with my own ideas. My thinking is that the problem is electrical specifically cooling fans. I have 2 fans and the manual calls them low speed and high speed. I know they both work by turning on the A/C. What I cannot see is when they come on and do I have 2 speeds at all. Problem is they never come on while the vehicle is stationary even at high revs as the temp never goes above 100 degs C.
With gauge in diagnostic mode I can increase speed up to 60 mph and the temp increases gradually up to 107, accelerate from here and the gauge goes to 114 then 121. If I hold steady here the temp drops back to 107 then I can push it up to 80mph and the temp falls back to 105. Wierd!
I understand that there should be sufficient air flow across the radiator to not require fans at all but logically they must come on at a certain temp. When I pull off the motorway the fans are running full blat but the temp soon cools to 100 and they stop.
Any ideas?

Solved it