Cooling fan quaestion

[Ralph Poplawsky <rlpplsky@ix.netcom.com>]

Hi Guys:

Until this year, I never heard the cooling fan ('91 200Q) run on any speed
other than (I think) low.  Recently, it occasionally comes on at an
extremely high speed, stays on for only 5 or 10 seconds and shuts off.
(The engine actually bucks when it turns on.)(Happens with air off, don't
know if it happens with air on)  Since my ECU was replaced this winter, I
was wondering if that could be the reason, or if some other part of the
system is beginning to fail.  Can someone please tell me what part
determines the fan speed and duration, and what I might look for??

Thanks:
Ralph Poplawsky
'91 200Q