My 00 Disco and has had some strange problems. About week ago I started and drove the Disco to my destination 30 mins away from our home. I shut it down, and then tried to start it about a minute later but it would not restart, it wouldn’t even turn over. I returned about an two hours later and it started fine an drove it home and did not use it that day. This has happened several times since then. There are no error codes and no indicator lights. When it won’t start there is no spark. Once it sits for an hour or more it starts fine. The other weird thing that happened is that the control panel for the temperature switched from Fahrenheit to Celsius.

I was thinking this might be the crank sensor. Please help.

 

Your battery is toast, replace it.
Here are the clues to that-when it happens it wont turn over, there wont be any spark unless you are cranking the engine trying to start it, your HVAC went from "F" to "C", easy to change it back, check owners manual.

If it was the crank sensor it would turn over but not start and your HVAC would not have switched back to "C".

Go to AutoZone and buy a new battery.

 

+1 beat me to it, not your CPS. Could also be a bad connection to the negative terminal on your battery but probably your battery is entering the final stage of it's life.

 

Battery was replaced last month optima yellow top, I can check the connections?

Could the battery be bad?

 

So, what have you found, were the connections OK?
Since you have not had a cranking issue, I would rule out a crank sensor. When you can't start it, how are the rest of the electrical things working?

 

Yes it could be a bad battery, or a alternator thats not putting out enough juice, or a bad connection, like the battery cables.
Check all of your battery cables, then have your charging system tested.

 

And remember: "it's brand new" is not always an indication that it didn't break: it's *still* worth pulling a charging test on the battery.

As it happens, though, *I just had this happen to me*, in between composing the first half of this posting, and remembering to hit 'Send'. :-)

In my case, it was a loose -- albeit very clean -- positive battery cable clamp. I didn't have a wrench with me (because I'm an idiot), but I did have a tire scrubbing brush, which had the companion advantages of a) enough weight to reset the clamp with b) a soft end, so I didn't run as much risk of breaking the battery internals *under* the clamp.

I'll tighten it properly tonight.

Same symptoms, though, and they're common: *just* as you turn the key, the truck drops completely dead.

+1