I noticed recently that both fans were not starting even after a long drive. Funny enough, the car does not over heat (temperature hovers at 80 degrees). I sent it to the workshop and they tell me that it a switch that starts it is bad. the switch is replaced and fan does not still start. Now the car has stopped and I'm told the fuel pump is bad.
When is the fan supposed to start ? even when i turn on the Air condition the fan does not start !

 

This is a very common problem. Just about every ML that pulls into the shop has this problem and the customer doesnt even know about it. You have a blown fuse!!! There is a wiring harness upgrade and bigger fuse for your fan problem..

For your no start problem.... Check your fuel pressure