Tarchon is the name of the legendary hero of the Etruscan city of Tarquinia, mentioned by Vergil. Tarḫun on the other hand is the Hittite god of weather and storm. There seems to be a commonly cited etymology that attempts to link the former with the latter and while I'm always cautious of these unproven claims, maybe this isn't so crazy. I just thought of something that adds to that connection so forgive me for brainstorming out loud.
Assuming that this etymology is sound, early Etruscans would have borrowed this term from the Hittites when they were still in Asia Minor in the second millenium BCE. This is an interesting idea because it ties in so well with my previous observation that Pre-Etruscan medial *-h- surfaces as the velar aspirated stop -χ- in Etruscan when following another consonant (cf. The loss of mediofinal 'h' in Pre-Proto-Etruscan). So does this mean that Hittite Tarḫun, a safely Indo-European name derived from Hittite tarḫ- "to conquer", was borrowed into the pre-Etruscan vocabulary as *Tarhun and later became Etruscan *Tarχun (attested on the bronze mirror indexed as NRIE 759 in the genitive case: Tarχunus "of Tarchon")?
 Dreyfus/Schraudolph, Pergamon: The Telephos Frieze From The Great Altar (1997), p.113 (see link).