My buick is releasing steam vapor though the vest and is leaking in the car from the dash, what could it be? and also it is leaking from underneth the passenger side.

No year, make, model given. If this only happens when you set the temperature control to a heat position, this isn't 'steam', but vaporized coolant coming from a leak in the heater core. Is your coolant level going down?

Most likely the "steam" is vapor from a coolant leak. Does the steam have a sweet smell? Does it leave an oily residue on the windshield when using the defroster? If so, you probably have a leak in the heater core.

If you can't see any obvious leaks around rubber hoses or radiator, it could be leaking though the engine block gasket into engine. Or even escaping through the rad cap when hot, leaking as steam slowly. Try putting a new radiator cap on (rad cap). As a quick fix, put Radweld solution into coolant. Any auto shop has it.

This is caused by a leaking heater core inside the dash. The vapor is from coolant.

The heater core is leaking and need to be replaced. It's under the passenger side dash behind the glove box.

The heater core split.

This indicates a fuel vapor leak in the EVAP control system. It means a very small leak has been detected. In fact, the leak can be from a hole as small as 0.04" in diameter. The (EVAP) emission control system prevents the escape of fuel vapors from a vehicle's fuel system. Fuel vapors are routed by hoses to a charcoal canister for storage. Later, when the engine is running a purge control valve opens allowing intake vacuum to siphon the fuel vapors into the engine

this would be a bad heater core. this is located under the dash on right side inside the heater box next to the blower motor the steam is acctualy radiator fluid that runs through it.

Yes, the pump is usually underneth the plastic ws wiper fluid. It takes +12v to operate and goes out quite often. Need to pull tank and check for pressure out put hose. Also could be a small leak losing pressure.
Good luck

Something is wrong. What does the steam smell like? Oil or antifreeze?
Look closely for coolant seeping onto something hot and vaporizing, if that's what you smell.
Check your coolant level and oil to verify if you may have a leak.