Mine works perfectly, I replaced both the amp and the actuator at the same time a few years ago (also checked all the connections). The whole thing cost about $5-600, took about half an hour, and did not involve any hillbilly engineering. If you decide to hack it, save the original parts for the next owner.

I don't know about you folks, but if I didn't want to "repair 1970's electronics" I would just buy a new car. This has nothing to do with the cost.