Heat not working in van

All I could think of is that you have maybe the wrong starter. My son in law was fixing my father in law's van, and he bought the starter for the van. The something happen, it will over heat, it just wouldn't turn the engine (you could hear the click sound and nothing else). When I checked it, I told him to exchange it since that was the wrong starter. He did and the van started with no problem. Also sometimes the stated works fine while unmounted, since it's not making any strength. But when mounted it just won't work. Try to get another starter just to make sure it's not the starter.

The blend air door stuck in cool position

Are you sure that it is coolant. Puddles form under vehicles where the AC drain is under the car. Check that the puddle is actually coolant and not water from the ac evaporator core.

could be a bad blend air door mode door

the heater coil is blocked up or hose is frozen

If you have two heater cores on your van, the front heater core may be stopped up by rust or stop leak if any has been put in it. It is a common problem i have seen. or your blendoor

Does the blower work? if not blowers shot..... if blower runs and no heat " and if the antifreeze is full " then the heater core is bad.....

you need to go to google an research the year an how to pull the engine codes an the van will tell you whats wrong with it hope that helps

Blend air door may be stuck. I removed a pencil from a heater box before. It had fallen from the dash, down through the defrost vents and jamed the door.

ive experienced this problem with my jeep... the geers not switching might be your tranny.... and the heat not working might be bcuz of the heater core... this will sometimes leak it most vehicles inside by where the passenger sits...