Hello. My name is Mark and I will be assisting you today.
This is a common fault on the transit.
You can try disconnecting the battery for half an hour to see if it resets itself.
If it doesn't then it will either need to be sent for repair or replaced. The repair is by far the cheaper option.
Sorry, I read it as dash /van losing power and al dash lights coming on.
Didn't notice you meant engine loses power.
Is there any time when the dash goes faulty and the engine doesn't lose power?
If not then it means the engine is actually cutting out first and then instruments all go to zero readings.
If you have two batteries on this vehicle then maybe one of them is starting to go faulty.
Just had a look at diagram and instruments are connected to engine ecu via the CAN bus network. I think you need to have instrument panel repaired.