Stereo/Amp wiring undersized

[2ridgebacks]

I have been having an issue with my Sony headhunt/Alpine amp. At anything over a volume setting of 23, the amp faults out and won't reset without powering down the head unit. I say it is the amp after reading that insufficient power will cause it to fault. I believe there is a power issue because Cobalt used 8 ga wire from the battery switch to the 80 amp fuse (or breaker) and then to the amp. Same with the ground that is run back to the common ground bus on the transom.
The Alpine owners manual specifies a 4ga power wire. Are you guys finding a similar situation? Also the Alpine manual specs a 60 amp fuse, I think. If that's the case, it's a bit odd for Cobalt to use a large fuse with light wire. Are you having fault issues with the factory stereo?
I made up a new ground, power jumper, and power cable today and got them half installed before heading to the ball field. I'll finish up and test tomorrow.

[Big Block Power]

It's not the fuse causing your issue. But will the wire melt before the fuse? Possible but I'm not a electrician but bfun is. When I installed my amp that was the first thing I noticed was the small guage wire for power and ground.
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Just posted a thread on the same issue. Maybe jeff will chime in. Jeff is it the wire or the amp.

[Silverbullet555]

I can't speak to their setup, but I run good power to amps in all my installs. Generally 0 or 00, but I'm excessive like that.

[2ridgebacks]

I wasn't concerned about the fuse BBP. The concern is the small gauge of the wire relative to the recommended minimum from Alpine. I was pointing out that Alpine recommends a 60 amp fuse with 4 gauge wire and Cobalt uses and 80 with 8 gauge. Doesn't make a lot of sense. Regardless, I'm swapping the 8 gauge for the 4.

[thunder550]

No harm in going to larger wire, since you're already part way through the swap I'd say finish it and see what happens. Boats are unique because of the length of the wire runs, much longer than a typical car so wires need to be larger to carry the same current. What's the wattage rating on your amp? RMS and peak?

[Big Block Power]

I wasn't concerned about the fuse BBP. The concern is the small gauge of the wire relative to the recommended minimum from Alpine. I was pointing out that Alpine recommends a 60 amp fuse with 4 gauge wire and Cobalt uses and 80 with 8 gauge.

I agreed with you on the fuse. I was just stating I think a 80 amp fuse is way to big for a 8 guage wire. And the wire may melt before the fuse blows.

[Bfun220]

I would run 4ga as the manual recommends. Then take your amps watts divided by 12 = the fuse size. If you use a breaker instead of fuse size your breaker at 150% of fuse size.

[Big Block Power]

I would run 4ga as the manual recommends. Then take your amps watts divided by 12 = the fuse size. If you use a breaker instead of fuse size your breaker at 150% of fuse size.

What B said!

[smokymance]

My old boat did this. How i fixed it was to run a direct power to the radio itself from the battery. Solved the issue. I am assuming the oem power wire to the head unit was undersized.