JBA, I had a Bart Simpson moment while I read your post. The information I downloaded on removal said to use a 1/4 drive 10mm socket on a short extension but when I saw that nut in plain view, and it was an 11mm well...Dohh! Makes sense now.
If you can, verify for me the order in which these IC's are installed. Holding the Amp with the 14 pin connector facing your chest and the component side up, they are located along the left side of the board. The first one closest to you is, we'll call it #1, a BD438. Behind #1 and rotated 180 degs , is #2 a BD437. Then there is an almost 2" space to get to the next pair. Number 3 is a BD437 and lastly, backing up to and rotated 180 degs is #4 a BD438. Is that right?
The manuals don't happen to have a schematic for this critter, do they? I know that the BD437 and BD438 can be purchased in matched pairs. Sometimes do to tolerence levels they have to be done that way. I wonder if these should be replaced in matching sets. I'll probably do it that way.
Micheal, thanks for the input. I haven't started testing the actuator but I suspect something is up with it. Can possibly a very stiff throttle cause the actuator to pull enough current to fry these things? My throttle linkage hadn't been lubed in years. It was very hard when I bought the car. I have since taken care of most of that. I'll post what I find out about it though.