L3130 randomly does this and then starts but this time keeps doing it. When keyin acc the lights blink on and off, sometimes they don't until turn to start. Battery shows 12vdc, battery drops to 6_8_10_6 volts during blinking. Both terminals and tractor frame ground cleaned. Stops blinking when 7.5 alt Amp pulled. But blinking with starter and alt unwired. Could be weak battery with no cranking amps but anyone have any other ideas? Acts like a ground short