First, when you turn A/C on the cooling fan should come on which proves the
electr. fan circuits are ok
You could still have other problems causing the fan not to come without the
A/C on but at least you \know the fan works

And yes, a/c cycles in defrost and defrost/floor mode to get humidity out of
the air

Hi Tom,
both times this occurred my wife was at work, this would happen on the
parking lot after a ridiculously long idle. I know the source of the steam
was blowover from the reservoir that ran down over the exhaust pipe, I saw
the evidence after the fact (coolant on inner fender where reservoir is). In
the times since I have tried to recreate the scenario, but to no avail. I
have yet to hear the fan start up just the same, which takes me back to an
earlier reply.
The cold season is here where we live (Alberta), so the fan may not be
wanting to start much anyway. Next warm day me and my trusty DMM will check
out the sensors and fan.

On another topic that may or may not be related, I have yet to have the rear
heat actually blow heat, only cold air. It has been suggested to me the
system is airlocked, which could cause a "boil over", so I am told. I have
no idea how to clear the airlock.

And last but not least, is it normal for the AC clutch to engage and
disengage randomly while sitting at idle, AC inside switched off?

Thanks....

______________________________________________

I have a little experience with Ford vans. More with wives (wife, only one,
so far). My wife might report a wisp of vapor as a "massive cloud". No, not
might, she would.

Just some things to think about...

Is she seing exhaust blowing under the car and out the front? Assuming the
wind is from behind the car.

Could it be a damp engine heating up?

Is there coolant on the driveway?

Is the coolant level ok?

Somebody asked if it overheated. You might point out the gauge to her and have
her watch it.

Better yet, drive the van for a week or two yourself and see what happens.

Let us know what (if anything) you find. I'm curious.

Tom

Not my doing, Jeff, it's the wife. I will make no attempt to explain her
actions, I just pick up the pieces.

Thanks again everyone, never considered the fan or sensors. Will try that
next.

Why are you letting the van idle so long? It's really not good for the
engine.

On 2 occasions, my wife reported a massive cloud of steam coming from under
the front of the fan, both time after a cold start-up and idle of approx 15
min to an hour. It appeared (I was unable to see this happen myself, and
wife's description was less than helpful) that it may have "boiled over" and
ejected the coolant through the reservoir, running down over the exhaust
pipe.

What could cause this? One suggestion was a sticking thermostat, any other
ideas or confirmations? I really can't afford a trip to the garage for trial
and error, and I can change a thermostat myself.

Thank you all...