Good day Folks

Veeman has been very helpful in my adventure of getting an amp for my van
i have selected an Alpine MRPF-250 4 Channel now my question i purchased an amp install kit with 12 guage power wire what size fuse should i run in this other purchases are 16 awg speaker wire to hook it all up once i make a harness

One other thing does anybody have access to a wire diagram for the 2006 Pontiac Montana Head unit i want to confirm the wires coming out of the back specifically the speaker wires

Oh and in case it makes a difference the van has Onstar plus a factory DVD Player

Thank you

after a quick search on the net, crutchfield recommends 8guage power wire for that amp. 12 is too small imo. you could probably get away with 10 if you were placing the amp really close to the battery, but since its a van i'm gonna presume you're gonna be running the cable quite some distance. don't starve your amp for power, or you'll regret it. in this case, you're better to go too big than too small.

for the fuse, look at the fuses on the amp (15Ax2, so 30A) and add a bit more for some headroom. so somewhere between 35-40A fuse.

here's a good reference:
Recommended Power and Ground Cable Sizes

Anybody know what the OD of 8 AWG & 12 AWG Power wire is i'm looking to purchase a rubber grommet to put in the firewall after i make a hole to run the wire

if you can, try to find one that is already there, then use a blade to cut a small hole in it. you can then push the wire through, it should stretch, which will give you a far better moisture seal than buying something the same diameter.

yup, run 8g for sure at least. and find a gromment on the firewall thats already there.