Here is the latest done today. Put in a new battery. Did the cable/battery terminal check with a test light. With the POS end disconnected, a clamp on the cable and a probe on the battery POS post I had a bright light on my tester. Checked all the lights, turn signals, four way flashers, heater radio to make certain nothing was on. Removed all the auxiliary bulbs in the door, dome and glove box lights. Ran the test again but now the light on my tester was about a third as bright, just glowing but also pulsating on/off. Started to think about the clock. Pulled the fuse for the clock and the dash lights and ran the test again. When I put the probe into the battery post the test light glowed very faintly and went off.
I removed it and tried it right away and no light. I waited 30 seconds tried it again and the light came on very faint for 2 seconds and went out. The cycle repeated. I then tried it with the NEG cable/post and no light at all.
I am wondering why on the POS set up the test light comes on very faint and goes out while I am attached.
I tried the test on the POS of another vehicle and nothing happened.