With the relay having a blackened terminal, it sounds to me like the starter has pulled too much current through the relay. It would only do that if it's near death or already died (the starter I mean). With many start and stops every day don't expect your starter to last as long as normal. Welcome...

Hey forum, Last week my alternator took a dump at 230,000 original miles, so I got one from a junkyard, got the readouts checked at O'Reilly's, and spent some time and profanity getting it in with the help of my Volvo-savvy brother. It seemed the dying alternator took my older battery with it as it ...