Thank Mr. Pedro,
I have a circuit tester, but do not yet understand how to use it. What I did do is spray all of the door hinges with penetrating oil and, after a time, re-inserted the cabin lights fuse. The problem seemed to have abated, but after driving the vehicle on a 2 hour trip that involved some steep, banked mountain curves, I can see that the problem is still occurring, and only when I make a sharp, banked right turn. When it started happening, I got out and slammed the doors shut and this seemed to curtail the frequency of the problem, but it is definitely still there. I have the service manual and can see the Electrical Schematics, but am not sure where to touch the leads of the tester in each instance.
I have a separate short in my right front headlight. It will not come on unless I open the hood and jiggle the wire leading to the connector – and then it only stays on temporarily. I have an almost identical salvage vehicle that I use for parts and know that I have a replacement for the complete wire harness leading to that headlight, but am unsure of where or how to diagnose the short and make the repair/replacement. Thank you in advance for any advice that you might be able to give.