I would also suspect that it has nothing to do with the electrical repairs you did. Most likely something else just decided to give up and causes these symptoms. Once, I installed a new (old) carb to our six banger Mustang and after the installation it ran very rough or not at all. Before the change it worked almost flawlesly. Well you can guess how many hours I put on the carb to check and recheck everything on it and later found that the condensator from the points type ignition decided to give up at the same time and caused all the problems.
Keep checking for everything that you haven't touched, which could cause same symptons, and I guess that you will find the problem
