Gearbox temperature warning light problem

Hi All

Yet another issue with my new Disco 2! The auto transmission temperature warning light is pretty much always illuminated once warmed up. It goes off I'm driving at a steady speed - say 70mph on the motorway but if I drive slowly around town or any faster then it comes on. The car is not being worked hard and not under much load - only one occupent.

I have changed the gearbox filter and oil and added an oil stabiliser but no change.

I'm am wondering if the oil cooler is blocked and how I could check this or if the temperature sensor is simply faulty. Does anyone know what the resistance of the temperature sensor should be?

Any thoughts??

Thanks, Paul

Just found some previous posts on this subject (why I didn't find them before I posted I don't know) and looks like the front temperature sensor is likely to up the spout.

Anyone know where the cheapest place for a replacement might be - I can't seem to find any listed.

Thanks

Paul

gear box produces more heat below lockup speed 50mph ish , so would explain why cooler at motor way than town , check cooler vanes are clear ,inside cooler will be clean auto oil is very detergent and if something was to produce sludge/debris it would be clutch pack and also turn oil black/ish ,until lock up drive is through high pressure oil between turbines this can never be 100% what energy is not transferred to motion becomes heat, switch more than likely playing up if oil clean and red

Thanks for the reply. Oil I changed was very clean and smelt fine - I don't think it had ever overheated - symptons seem to point to switch.

Any idea where I can but one - I can't seem to find anywhere that sells them?

At this price u can replace it to checkhttp://www.ebay.co.uk/itm/landrover-discovery-td5-Auto-gearbox-temp-sensor-/200658605527 ...though it might be a bit hard to get to it