I just want to share this story so maybe someone out there can learn from my mistake.
I had to replace the ECM on my 89. About a week after I did it the heater/ac blower motor started to blow constantly at full speed whenever the key was in the on position. I have the auto climate control. I posted the problem here about a month or so ago and the general consensus was that the blower control module in the evaporator case went bad.
I actually was able to borrow one off of a friends car and it madeno difference.
It turns out that in my hast to get in out of the cold I inadvertently pinched the wires that run to the heater door control motor in the bracket that holds the ECM in place. Once I found that everything came back to normal.
Hopefully this will save someone from a major headache down the road.