I had my entire dash out, rebuilt the clock cleaned and freshened up everything and reinstalled it. There are 3 back ground wires on my harness (70 SS). I put everything back the way it was fresh, clean and tight. Still no amp-meter gauge {I have the actual gauge, not a light} after replacing the battery, alternator and rewiring the location where the external regulator used to be, 3 different times I was beginning to get a little upset. On a whim I pulled apart the main connection to the fuse box cleaned all the male and female connectors gobbed it up with some dielectric grease and “presto” amp-meter works all the lights on the car were brighter and the radio noise was gone. – Something to consider.