I have replaced one relay on DS4510 so far. Original battery is still good to go. However, I have adopted a starting process that I don't fully understand but seems to always work. Whatever the weather, I turn the key to initiate the glow plug (warm weather this is brief, colder weather, I wait 20 seconds or more). Then turn the key back off and then over to start. Cranks and fires every time. If I go from glow to start, the connection is not made to the starter (no turn). I hear the relay click every time I turn the key, but it now seems that I have to perform this two-stage process. I don't mind it -- it always works.
re: lighting plug- ditto on P/N -- I'd like to find the mating connector and wire up some LED lights for snow plowing.