Recently several times when I tried to start the engine the starter contact did not engage (starter relay click yet there was no current passing through). After a few tries the contact inside the relay finally engage and starter turned. I ordered a new starter relay from Van's and installed it. I did put a diode on the starter relay and did not expect the contact to wear out so quickly (total hobbs time: 877 hrs).

Upon closer inspection I found the Hall effect current sensor must be hitting the starter relay. The sensor is installed on a fat cable connecting the input side of the starter relay (also the output side of the main and aux relay). It is a ring type (about 1.5" dia) sensor over the cable. Due to the wire routing it is very close to the starter relay. A small section of the ring is missing. Since it is hard to relocate the sensor I am going to put some RTV between the sensor and the relay to hold it in place.