Accessory power wire question.

Wayne Waldrep

Before I post a pic, do you have one of yours?
Dirt-Old 20+Year Member
Apr 14, 2003
1,288
698
143
Cuba, AL
So I'd like to wrap up a few items in my car in a few weeks such as finally putting the audio system and the two 12v power ports back in.
Let's say I'd like to make one wire run from inside to under the hood and use that wire to feed a distribution block for both things above...and maybe have a spare spot for something else later. I'm conservative so there WON'T be 4 amplifiers and a 1000w game spotlight, ever. My question is, does this sound like a good idea? Has anyone done this and if so, gimme some details.

Disclaimer:
My thoughts on wiring... Wiring is sized to carry a certain load of the attached items. Fuses are sized so that the wire doesn't burn. (All these numbers are complete rubbish and for example only). So if you have, for example, 10 amps draw from the items and the chart says you need an 8 gauge wire for 20 amps, you have double the wire size, which is fine. The wire won't burn until more than 20 amps are applied, in theory. So if you put an 18 amp fuse in, you are covered. Some people want to mistakenly fuse based on the 10 amps that the equipment draws. That is incorrect. If the wire can safely support 20 amps, why fuse down near 10 amps? Any flaws in my disclaimer?

Been dealing with enormous stress lately so please hold words like idiot, stupid, moron, etc to the bare minimum...lol

Thanks!
 
Last edited:
  • Sponsors (?)


I think a 4ga wire from the battery would be fine . I ran one PPI art series and a us amp for 6 years like this with no issue.

You could branch out to 8ga to the amps from your block as it would most likely be located real close to them .

I just installed a usb power port in my console and I used the cig lighter circuit as it’s already fused . Hope this helps
 
  • Like
Reactions: 1 user
Mustang-Power-Supply-Diagram.jpg

This is what I'm thinking. I left wire gauge off in case someone down the road looks at this and were to use my numbers in error. Don't want to torch their car. And for reference the chart below is off of Crutchfield's site.

Gauge-Chart.jpg
 
Your Stock radio harness doesn’t power your head unit anymore ?

Your diagram is fine like I said I think 4 is plenty then 8 for your amps off the dist block
 
Your Stock radio harness doesn’t power your head unit anymore ?

Your diagram is fine like I said I think 4 is plenty then 8 for your amps off the dist block
No. I had a buddy long ago that worked at a stereo shop. I bought a stereo to put in the car and he insisted on putting it in for me. I've been trying to recover ever since...lol. And I don't have amps. I have one SoundStream 5ch that I'd love to put back in. It has a dead channel and needs a repair. That would be the only amp I would ever put in it. More than likely will just run radio power. 4 gauge would definitely cover it. 8 gauge would cover 65amps for a 10'-13' run. I'd never go over that.