[Skip Fix]

So pondering battery in the trunk wiring. So theory is have the Ford/duty rated solenoid in the trunk so there is not a battery cable hot the length of the car.

But to have good juice to electronics, electric fans, water pump, the rest of the car that is all at the front you would have to have a cable large enough supplying those right? Grant it, it could be a click smaller but still a decent sized cable.

[Lee]

I've used 2/0 for cable to the starter, for trunk mounted batteries. But the main power wire does not need to be nearly as big. A decent chart is found here: http://www.offroaders.com/technical/...gauge-to-amps/

You can use a circuit breaker or fusible link on both ends of the main power wire, to protect against electrical fires.

The starter wire is dead when the solenoid isn't energized, and I don't think a circuit breaker would be reasonable on a starting wire.

[Skip Fix]

But if using big amp fans you are still going to have maybe 6 or 8ga hot wire that can pass a lot of juice in a wreck too.

[padgett]

Why the SCCA requires a big disconnect for the battery AND generator field on the outside and very visible.

[Lee]

"But if using big amp fans you are still going to have maybe 6 or 8ga hot wire that can pass a lot of juice in a wreck too."

Not if you have a fusible link or a circuit breaker on both ends of the main power wire (the wire connecting the power junction under the hood to the battery)

[67Fbird]

Yes you still need a big HOT wire running to the front to feed a distribution block or buss bar. The difference is it will be routed inside the car and not really subjected to the outside environment. Max you probably need is a 6 ga wired from your cut-off to the front of vehicle.

[Mean Green]

4 awg welding cable is plenty for a starter. I don't use the Ford solenoid, because it is an extra point of possible failure.

6 awg to the alternator, because I like to run higher amp alternator.

6 awg to a relay panel for pumps, fan, etc.

[Mean Green]

Pic

[Scott Stoneburg]

I have run my cable front to back for 30+ years with no issues. Route it along the frame and it will be up high enough to not be in danger. As for the size, mine is 2/0 welding cable. which is way overkill, but its what I had.

[ta man]

With so many good quality lightweight batteries on the market how many guys are mounting their batteries near the firewall or running dual lightweight batteries?

[67Fbird]

^^^^^ welding cable" being a different animal..... flexible ...more copper....

just saying

[67Fbird]

^^^^ oh oh i am....old car had 10.75:1 compression iron head street pig....2 red tops in the trunk with 00 welding cable for the POS GM starter.....once I got the mini starter....gear reduction...all way well.

[Skip Fix]

I know one Pontiac SS that moved his lightweight battery back up front to get weight off the car with shorter cable and smaller battery..

[Tom Vaught]

I have two Pontiacs that are using welding cable from the battery.
In the convertible, the cable was pulled and routed thru the frame.

In the Chassis Car, I ran the cable thru a conduit that was attached to the frame rail.
The chassis car was built with a lot of straight rectangular tube (steel).

Tom V.

If I remember correctly the Herb Adams SCCA Tempest had the battery in the trunk and the battery cable ran INSIDE the vehicle and met SCCA requirements.

[Mr Anonymous]

Dave Freiburger had an excellent video about wiring on Roadkill or Roadkill Garage when doing his F-Rod street rod project. Probably he best info and logic backing it up that Ive seen in years. I don't do it his way, but his approach makes sense. Look it up for more info.

[mgarblik]

When we wired the Grocery Getter race car, I made all my own harnesses. It had allot of wiring for a race car because of all the nitrous and timers, digital ignition.I wanted a system that would be bullet proof reliable under the most extreme conditions, and be easy to trouble shoot. So I wired each circuit with it's own discrete power and ground wires. No common ground giant splice connections. Each circuit had a separate ring terminal connection to a welded ground stud on the frame. I think we had 5-6 ground ground studs with the grounds in a logical order. Our wiring rules were NO SCOTCH LOCKS allowed within 20 feet of the race car, trailer or tow vehicle!! No spade terminals, ring terminals only, or weather Pack connectors. Only heat shrink terminals used in every location, power and ground. In 18 years of racing that car, the only electrical/wiring issue ever was an MSD factory terminal connector on the digital ignition that went to the crank trigger. FWIW.

[Tom Vaught]

Originally Posted by Lee

The starter wire is dead when the solenoid isn't energized, and I don't think a circuit breaker would be reasonable on a starting wire.

1) If the solenoid you are referring to is the Ford Solenoid and it is located close to the battery in the trunk, the the Power Cable from the battery/solenoid to the starter solenoid is not energized, as you posted. I had the Battery on the trunk wired that way to the starter solenoid for many years. And the Ford Solenoid will last forever with the few seconds of being energized each start event. No need for circuit breakers there.

2) The Power Cable for the rest of the Electrical system can also be addressed with with a Power Relay board with 40 amp relays for the different circuits, Ignition, Headlights, Start Switch to the Starter Solenoid, Gages, etc.

And all of the power will be dead at the battery if those 40 amp relays are not turned on. Buy the good continuous duty relays.

Tom V.