Hi Paul. I have no experience with the '82 but I have had electrical gremlins in both my '72 and '87. The most common problem has been bad or weak grounds. One time it was the ground cable itself. The washer on the negative terminal on the battery cable was corroded. Pulled the bolt out of the cable and thoroughly cleaned the contact on both sides with a Scotchbrite pad (steel wool would also have worked). It's also possible your battery has a dead cell or an internal short. Sometimes, when a battery sits for a long time it will take a charge but flakes of lead oxide will fall off the plates and short out the battery. If you have a known good battery from another car to try, it might be worth a shot.
