If I have a 4Guage power wire will their be a problem if I use an 8guage Ground wire? And why do I need to put the fuse in the Power wire within 18" of the battery It would be much simpler to mount the fuse in the trunk with all of the other Connections.

Thanks

 

depends on the amp and how much power it draws for the ground. you fuse the wire upfront because if it was in the back and it rubbed trough and shorted out anywhere between the battery and the fuse your car would catch fire. always ground near the battery and use the correct fuse.

 

Sinister is correct. Can be very dangerous on the fusing. As for the power wire, you should always run the same size power and ground wire. The amp is only as strong as its weakest link. If you have smaller ground than power, then your power wire will be bogged down. Maybe you can get away with it but, I would not try it. Just not good practice.

 

Thanks for the info.

 

the reason for 18"....
When that small wire over heats and blows a fuse, the closer to the battery the better. its better if only 18" melt of that power line and catch fire as opposed to 10 feet cathcing fire and igniting the entire vehicle. The closer the fuse is to the battery/12v source the better

 

EXACTLY! I have seen people use smaller grounds and theres never been a problem with their system. But like he said it's not good for the system either. Bascially like drinking a big gulp with a coffee stirer.

 

but also if you have a 200 watt amp you would only need a 10ga wire and 4 ga would be over kill. but if you have a 1,000 watt amp thenyou need a 4ga. it just depend on the amp.

 

distance adds resistance... 8gua is the minumum I've ever run for anything in the trunk.

Also, I think someone typoed above..your negative wire should be grounded as close to the AMP (not battery) as possible. The shorter the ground wire, the less likely hood of ground loops or interference.

 

Thanks for all the input, I have installed the amp with both power and ground at 4ga. and the fuse less than 18" from the battery, the ground wire was about 28" so hopefully everything will work OK. Just finished installing the speakers in the passenger side door, hopefully if the rain holds off will get the drivers side done tonight after work.

If I had just read the instructions for the amp they say to use a 4ga wire for both.

Thanks,
JJ