Ignition breaker tripping

Ignition breaker on dash tripped today about 4 or 5 times over 2 hours. after each time it can be reset after about 30 seconds, then i can start the engine and run it like it never happened. There seems to be no similarity between each time- once was on startup, once at 30 mph in straight line, couple of times on tight slow turns. Any ideas what can cause it to trip? No unusual loads- even the radio breaker wasnt turned on. Connectors on back of breakers are a little corroded but im still seeing 13V on dash meter.
Thanks, peter.

edit: still running protec, not sure if this could be going bad.