164 Auto Transmission Problem?

[Bob Abhalter <gt1300jr@domain.elided>]

Over the last month or so I have noticed that the transmission fluid 
cooling fan on my 90,000 mile '91 164L has been operating with increasing 
frequency. Over my first 3-1/2 years of ownership, I rarely, if ever, heard 
the fan operate. Now the fan is on and running (noisily) at the end of my 
daily cross-town commute. I'm not sure what's up. The fluid was changed 
last year and smells and looks normal today. The transmission seems to be 
shifting normally, but now that I am tuned into this problem I am thinking 
that I feel more abrupt down shifts as I decelerate. I'm scared that I may 
be facing impending transmission failure. Am I correct in thinking the fan 
rarely cycles in normal use? Maybe it's the fan that's failing - it seems 
to draw heavy current (voltage gauge drops to ~10-11volts at idle with fan 
running). Any opinions or other data points?

Bob Abhalter
Grand Rapids MI

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