<E30> Intermittant Fan Speed Problem

[SMILLER@xxxxxxxxxxxxxx]

My wife drove my car over the weekend while I used her Durango to
tow a trailer and stuff.  Monday on my way to work, I discovered that the
heater fan only worked on the "high" setting, but not the other settings. 
My first thought was, I wonder why my wife didn't say anything about
this?  But maybe it wasn't a problem for her.  Whatever, no problem, I
figure, it's just the resistor pack, I can replace it, and in the mean time, if I
really need the fan, I'll just put it on "high" and turn the stereo up real loud
to compensate for the noise.

On the way home I turned on the fan and discovered that all 4 speeds
work now.

So what would cause this intermittant fan speed problem?  If a resistor
was fried, it would either work or not work, right?  Maybe a bad
connection?  Which connection should I check, at the switch, at the
resistor pack, or somewhere else?  Has anyone out there had this
problem before?

As always, TIA for any advice.

Scott Miller
Golden Gate Chapter
BMW CCA #44977
1990 325i/is hybrid

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