Trunk mounted battery...where to run alternator output?

[randy]

now your starting to make me think it would be a good idea to run a inline fuse from the battery to my bulkhead

[Woodrow]

Originally Posted by cpd004

Are you saying you used a Ford type solenoid?

Yes, using the Ford solenoid.

[cpd004]

Mad Electrical has 2 kits that others have recommended: TM2 and ST1.

On a side note...I was looking at my G8 which has a trunk mounted battery and it appears the + side is live all the time. It appears to go from the battery terminal along the drivers side of the car to a positive distribution block and then on down to the starter. It also appears to be at most a 2 gauge wire.

[WSSix]

I designed my own system. It's similar to the Mad Electric one. I have a 2 AWG cable going from the battery to a Ford style starter solenoid that's mounted behind the battery. Then the battery cable goes all the way to the front. It's only live during cranking. The ground goes straight to the frame rail after coming off the battery.

The alternator return is 4 or 6 AWG and goes all the way back to the battery through a 100 or 150 AMP circuit breaker that's also mounted behind the battery. Yes, the alternator cable is live the whole time. However, you can't easily put a circuit breaker/fuse on the starter cable so protecting the alternator cable is easier and smarter IMO. Something goes wrong and the system is disconnected and the car is protected.

I have a junction post on the firewall for power take off to the rest of the car. It's below the AC box between the frame rail and firewall essentially. It's well protected and a pain to get to if needed. I also have a smaller circuit breaker right off the post for the rest of the car. It's much smaller than the alternator one and protects the wires between the junction point and fuse panel in the interior. The electrical fans have their own circuit breaker and relays mounted to the inner fender on the driver's side. Off hand, I believe that's the only power circuit not going to the inside.

My attitude towards more circuitry is to not play games with protection. You have to protect the wires to what their capable of handling. I could have eliminated the circuit breaker off the junction post on the firewall and allowed the circuit breaker in the trunk for the alternator to handle it. However, it's a big breaker. The wires off that junction post could melt before they trip the circuit breaker in the trunk. An inexpensive and small circuit breaker is money well spent IMO.

[cpd004]

So the crank wire would now go to the Ford solenoid in the trunk and would not need to go to the starter any more with this set up.

I've read people using 4 and 8 gauge from the alternator back to the battery.

I like the idea of breakers over fuses, although a handful of fuses wouldn't be much to carry around either way.

One install I saw uses Marinco breakers. They are normally used in marine applications but look better than some of the automotive ones I've seen. They are a few dollars more though.

What brand of breakers did you go with?

[Vince@Meanstreets]

Originally Posted by cpd004

So the crank wire would now go to the Ford solenoid in the trunk and would not need to go to the starter any more with this set up.

I've read people using 4 and 8 gauge from the alternator back to the battery.

I like the idea of breakers over fuses, although a handful of fuses wouldn't be much to carry around either way.

One install I saw uses Marinco breakers. They are normally used in marine applications but look better than some of the automotive ones I've seen. They are a few dollars more though.

What brand of breakers did you go with?

No need to add the Ford solenoid on an LS starter. You are only adding weight and easing the job for thieves. People started adding Ford solenoids to combat starter heat soak. Which is non existent in modern LS starters.

On trunk mounted battery systems, I like to run a bulk head stud on the firewall near the starter. Then just run a 10" long 2 ga to the starter. 8 ga to the alternator from the firewall bulk head or the radiator support power feed. I run a radiator support bulk head to feed the fan and headlamp relays.

[cpd004]

Live all the time? This is the way OEM's do so I don't see why it should be a problem here. Do you have a pic of the bulk heads you use?

[Vega$69]

Originally Posted by cpd004

Live all the time? This is the way OEM's do so I don't see why it should be a problem here. Do you have a pic of the bulk heads you use?

The OEMs do it because they are designed from the get go to do it.

I run the ford solenoid for the started wires and a fusible link on the ALT wire

[MtotheIKEo]

I used to use the circuit breakers when I designed electrical systems for utility trucks and cranes. They work awesome, are compact, and you can easily disconnect your electrical at the battery if you are working on it without any tools.
http://www.amazon.com/Bussmann-CB185.../dp/B001PT7XBE

[Vince@Meanstreets]

Originally Posted by cpd004

Live all the time? This is the way OEM's do so I don't see why it should be a problem here. Do you have a pic of the bulk heads you use?

Originally Posted by MtotheIKEo

I used to use the circuit breakers when I designed electrical systems for utility trucks and cranes. They work awesome, are compact, and you can easily disconnect your electrical at the battery if you are working on it without any tools.
http://www.amazon.com/Bussmann-CB185.../dp/B001PT7XBE

those work fantastic...There was a thermal type that I was researching but can't seem to find right now.

cpd004, firewall pass through... http://www.summitracing.com/parts/sum-g1431-red