The radio in my Toyota Land Cruiser 100 vx Ltd wont swith on. The navigation maps are fine as are all the other screen displays. I cannot even find the fuse for the radio. When i go to the radio screen i get the message "Audio Off" and pushing the volume/on-off switch does nothing!

SOURCE: 1997 Toyota Land Cruiser rain water leak

i had the same problem. Flushed the sunroof drains, replaced the windsheild, and weather stripping on passenger and driver side doors. Car is still leaking. No one can figure it out.

SOURCE: H4 switch, engine

H4 stands for "4 wheel drive; High Range".

Regarding changing to a diesel, you are in for a lot of problems, I am sorry to say. There is a multitude of things that have to be changed, IF the diesel could bolt to your transmission, which it will not. This would be a really,REALLY expensive undertaking.
Personally, I would not attempt it.
Sorry again.

SOURCE: quantity of engine oil used in 1 HD engine toyota land cruiser

The Landcruiser 1HD engine uses 9.3 liters of oil with the filter. The oil is replaced every 5000Kms.

SOURCE: Land Cruiser front wheel

Just check your car does not have differential locks, in theory they should not come on without being switched on but they can fail in the 'on' position. Lift both front wheels and see if the steering is stiff with the engine running, if it is then the 'locker' is not to blame. If it is now free then look at the locker and see if it has seized,

regards

Dave

SOURCE: 2004 Toyota Land cruiser key programming

you need to take it to the dealer so they can program the key to the car which requires there software. hope this helps