Just lent a friend my P-bass since his bass cut out on him. I offered to look at his bass while he borrowed mine: It's an 80s Kramer bass with EMGs in a P/J configuration. It's US made and a set neck, so I assume it was a high end bass in it's day. Plugged into an amp there is little to no output. You can hear when I tap the pickups with a screwdriver. My passive Fender Jazz Bass is at least double the volume. I bought a brand new battery that tests 100% on my Batt-o-meter, but when I put it in the bass and test the battery through the Batt-o-meters 1/4" plug, it reads that the battery is <40%. Any ideas? It has a 3 way pickup selector and that seems to function with my barbaric screwdriver tap test. Does it sound like a wiring problem or pickup failure?