15A stereo fuse keeps blowing

[Sm0Ke]

After getting my 07 VLX back from my local dealer I have had an issue where my stereo wasn't switching on. Traced the issue back to the 15a fuse at the back of my clarion m455a head unit, easy fix (or so I thought). Upon replacing the fuse it blew, figured it must of been a fluke so I replaced it again. Yet again it blew, unplugged the harness from the back of the head unit and plugged a 3rd fuse in, No issue, plug harness back into the head unit and boom up she goes again.

Could this be an earthing issue? Its difficult to trace behind the drivers arm rest to see if theres an issue behind there. but from what I can see at the cradle everything looks fine.

Its worth noting that this issue has only arisen after i had an oem 70amp replacement alternator fitted at service.

Just going on the weekend here and the dealer isn't open, and with an hour drive back there it'd be great if it was something I could sort out myself.

Hoping its not the head unit pcb itself. Anyone with a bit of knowledge that could point me in the right direction would be greatly appreciated.

[MLA]

That fuse would blow either due to an internal short in the head-unit or excessive current draw in the head-unit. Either way, this is pointing to an issue with the head-unit.

[grandude]

Was the boat covered while at the dealer? Did the head unit get wet or boat get rained on? My dealer covers every boat that comes in with one. I have heard him express frustration at having to leave boats open when customers don't bother bringing in their covers.

[Zombie]

Also, recheck the wiring at the harness and see if any wires are loose and touching each other causing a short.

[Sm0Ke]

Thanks for the replies guys, it was only at the dealer for 4hrs (couldn't have gotten wet). I have double checked the wiring harness and theres nothing touching, I would of thought if that was the case when I unplugged the harness from the head unit it would also blow the fuse. Instead its only when I plug in the head unit, introducing that circuit that makes it blow. The more I look, the more I lean towards it being an internal fault inside the head unit.

My biggest concern is how do i prove it was due to an alternator change at the dealers? With the main breakers not tripping and only the 15a fuse blowing on the head unit, how could it have been introduced through a power spike? It would seem it wasn't sourced from the battery side of things rather than a fault originating from the head unit itself? Just amazing coincidence perhaps?

Either way I don't like my chances on arguing that it was working perfectly fine when I dropped it off If i cant find something tying it back to them changing out the alternator.

Might be time for a new head unit (so boring on the water without tunes!)

[Sm0Ke]

sorted the issue by purchasing a new head unit. Plugged in and fired up straight away. Ill have a talk with the dealers tomorrow.