Odd cooling problem

[amalventano at sc.rr.com (Allyn)]

>  Actually when you stop the engine the temperature will raise. Because
>  there's nothing to cool the engine, no water flow inside. Haven't you
>  noticed that after you cut the engine the fan start working foar a minute
or
>  two?

the fan kicks on, but this is not due to the usual temperature switch
(radiator), it is due to a after-run temperature switch in the cylinder
head. the intended purpose of this is to keep engine bay temps at a
reasonable level when the engine is first shut off. this was done because
wiring was becoming brittle in southern cars. engine bay ambient was getting
>300f in the first few minutes after shutdown.

an alternate cause of the fan running is if the a/c was on. the a/c high
pressure switch keeps the fan on after shutdown to help drop evaporator
pressure, preventing damage to the a/c parts.

Al