My experience was odd.
Blower fuse failed, replaced fuse.
Fine for days, then intermittent function.
Replaced blower w/ salvage unit.
Fine for days, then intermittent function. Code 411, 418 [I think it was].
Replace power stage with new unit.
Fine for days, then intermittent function. One last failure.
Pulled ECC, unplugged and plugged in wires.
Everything fine since. Knock wood, but it's been weeks.
I can ship you my old power stage for a nominal fee; however, although it never fully failed as described by Lee, the resisters show evidence of "leaking and oozing", and intermittent function is strongly suspected.
Even though my car has 160K miles on it, if I was doing it again, I'd buy a new blower and new power stage from Darrell Waltrip. Just like I should have bought a new radiator fan last year, but put in a salvaged part, ad did the same last week [after enduring driving with the windows down and the heater on, and scrambling for a replacement fan].
If JRL's upcoming '97 850 T5 had appeared three weeks ago, I might have jumped.
However, at this point, I'm committed for another year or three.
1994 850 Turbo Sedan. 202,000, and getting more experienced, not older. - sold