can any one tell me how to unlock the fly wheel on a 1994 gmc van auto transamissionthank you?

Umm, do you mean engine or transmission? Doesn't sound good. How's the oil and coolant levels? Bet they where low. I if they are good look at the transmission pump. Sorry.

as mr know it all said flywheels or flex plates don't lock but they are connected to the engine, so you may have a bigger problem. try this first if you can access the flywheel with out taking out the starter, use a large screwdriver and see if you can turn the engine by hand, if you can it's not the engine it's the starter. however if it does not turn then your engine has seized

Could you elaborate?

Automatic transmissions don't have flywheels.

Flex plate, sure, but they don't lockup.

ADDED:

Perhaps your engine is hydro locked?

Click this. http://en.wikipedia.org/wiki/Hydrolock

It explains it very well.

Too much to copy and paste into YA.

it is quite possible that the motor wont turn if the flywheel wont turn. whether it is a auto or standard

Visit that website www.unlocklertool.com