'88 2.5 radiator fan turning on too quickly

After driving my 1988 Voyager a few blocks today at approx. 40 degrees
ambient temperature, I popped the hood and left the engine running. The
upper radiator hose was still cold, meaning the engine had not reached
anywhere near operating temperature. The radiator fan then clicked on
and ran for probably a minute. Neither the A/C nor the defroster was
on.

I know that the SMEC turns on the fan through the fan relay based on
information received from the coolant temperature sensor. The sensor
has been replaced probably within the last year.

Any ideas? I doubt that this could impair driveability, but it just
seems odd that the fan is turning on so soon and while the engine is
still relatively cool.

Thanks everyone for your input.

 

This is normal. The fan turns on early when the car is stopped to blow
condensation off the radiator. This prevents "steaming", in which
condensation evaporating off the radiator forms visible steam coming out
from the edges of the hood, looking like a cooling hose has blown.

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__o
Keep on Ridin' `\ <
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* Al Williams *
* San Jose CA Chief Cyclist, DNRC *
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