A few months ago I replaced the odometer gear and the odometer was working again, but then the gauge cluster started losing power and all the gauges would just go off. Gauge lights would be on but the tach would be showing zero revs, speedo at zero, gas and temp gauges would fall and the odometer would quit turning. Usually unplugging all the connections in the cluster would fix it for a while but lately it hasn't been, the needles have started to drop but jump around (if I'm going 70mph the speedo needle will kind of bounce around at 20-30mph) and the battery warning light glows bright red and the gas gauge raises and falls all the time even if the rest of the gauges are working.

Aside from mechanical maintenance the car has a new alternator and battery. With the gauge cluster pulled out if you give a slight pull on the round barrel connector all the gauges work perfectly. Are these symptoms of a bad ground or bad sender?