My brother and I drove up a large irrigation canal today and afterwards my transmission temperature warning light came on. This is on a 1997 Discovery. The water was probably as deep as the top of my bumpers. I've heard the sensor can short out when it gets wet but havent seen any instructions on how to fix it. Any ideas?

 

When you restart the truck and let it warm up, is the light still on? If so te switch has gone bad. If it is off but comes on again, you have a failing switch and it should be replaced.
Mike

 

It just stays on all the time... no matter what... hot, cold, warmed up, whatever.

How can I prevent this from happening again? I kind of want to be able to drive in water. Also, where can I find the sensor?, maybe the wire got pulled off or something.

 

Ok, now the warning light is off when I first start driving but turns on and stays on after about 10 mins of driving. Fluid in the transmission is full... do I need to get the trans serviced?

 

Sounds like the tranny temp switch is going bad. I take my truck in 3' of water with out a problem but on yours maybe the switch is no longer water tight.
Mike