I wonder if there would be some other way to identify such a failure. I
wouldn't mind having an audio alarm of some type in addition to the
light for low coolant warning - but if a belt breaks and the pump stops
turning  and pumping - like  you say - you may miss what the real
problem is until it's to late. As a matter of fact - until you mentioned
this, I don't think I had ever even thought  of it. Now I am aware, I
know to stop immediately when that alternator light comes on and check
things out.

To add to this discussion just a bit - pilots are trained to do an
instrument panel scan every few moments. Look out side, look at flight
instruments, look outside, look at the engine instruments, look outside,
look back at the flight instruments. That scan is a sweep, outside to
the left- then inside. Outside straight ahead, then inside. Outside to
the right, then back inside. Next it gets reversed, but it's constantly
outside, inside, outside, inside. This assures both for flight safety
and for safety of the airplane itself - it is very closely monitored.
All of us would do well to develop a similar procedure. The frequency of
the sweep of the engine instruments is not as critical in our beloved
vans as for an airplane, but can definitely pick up on changes from one
sweep to another - before something bad can happen. It is astonishing
the number of people who just get in their vehicles and just drive,
never ever monitoring the engine until it acts up or quits.

Do Happy Scanning, Have  Happy Driving!

John

John Rodgers
Clayartist and Moldmaker
88'GL VW Bus Driver
Chelsea, AL
Http://www.moldhaus.com

On 9/22/2011 9:03 AM, Dennis Haynes wrote:
> The other major coolant
> system failure is loss of water pump drive. This is covered with the
> alternator warning light but the operator has to know to check that. Often
> the light comes on and the driver thinks that only the alternator failed and
> keeps driving until the overheat-steam-blown hose event occurs.