lucasp

Has anyone re-located their battery to the trunk? how would you run the wires? is it safe with the gas tank being so near? just looking to clean up the engine bay and secure the battery. Pix would be great if available. ThanX

Help

ozarks06

Should be lots of post about this - try a search.

Edit: Actually there aren't many on this forum. They're all on the other one .

Here are a couple:

https://mustangforums.com/forum/clas...elocation.html

https://mustangforums.com/forum/clas...elocation.html

Here's the mother of all battery threads on the other forum:
http://forums.vintage-mustang.com/mo...tion-fuse.html

The safest way to wire it is to put a solenoid in the trunk and run an unfused 0 or 2 gauge wire from it to the starter so that it is only hot when starting. Then run a smaller wire (I use 4 gauge) through a 150 amp (or smaller) fuse to power the rest of the car. If you get in an accident, the fuse will blow if the wire is shorted to avoid a fire. If you have an unfused heavy wire to the starter (solenoid in the engine bay) and have a fire, you might have a 1000 amp welder going until the wire burns in two, the battery explodes, or your car burns to a crisp.

66JameStang

We relocated mine to the trunk to provide more space in the bay. We ran the positive and negative down the passenger side of the car attaching them with clips and self tapping screws. the battery is mounted into a battery box in the passenger rear corner on the flat area.... I know this is "real" descriptive! I will try and take some pictures of my setup tonight and give them a post....

urban_cowboy

Yes. It is pretty easy. Keep the ground wire short. Run the positive lead along the subframe attaching with insulated clips. Put a disconnect on the battery cable in case of a ground out, and make sure the battery is covered so nothing can fall on it to short it out.

hightower2011

davesanborn made a great post in this thread with pictures as well. It's helped me understand and I plan to do the swap in the future.
https://mustangforums.com/forum/clas...ocation-3.html


I still need help figuring out the solenoid deal...

PaulS

Unless you changed to a later style starter (with the solenoid mounted on the starter your solenoid wiring is the same.

JMD

I am not a big fan of the chassis ground used on the kits, I always run a dedicated ground from the battery to the starter mount bolt.

I catch all the other grounds off the end of this cable.

It seems as if I always put the battery in the trunk these days, imo batteries just clutter up an otherwise nice looking engine compartment.

On my 39 I used a "latching solenoid" along with a wireless remote to make a kill switch for "security reasons"...

MustangBradley

Using the body as a ground path for the staring circuit is not a good idea. Ozarks06 suggestion about having the solenoid in the trunk is very wise, and his reasoning true. Run a ground cable of the same gauge wire as the positive to the block. Remember, you are running close to a 1000 amps (worst case) through those wires, so not only do they have to be able to handle that much current, but they must also be protected. Don't skimp on the wire.
If you run a body ground, the return path to the battery has much more resistance compared to a large copper wire, thus your starter won't get all of the juice it could get.

I used a DynaBatt battery, which is about half the size of a normal battery, and it has never failed to start the car. It tucks away nicely in the engine bay and I have nice, short wires to the starter and block.

If you are set on putting it in the trunk, follow Ozark06's advice. Or start carrying a fire extinguisher!

PaulS

If your starter is pulling 1000 amps (thats 12,000 watts) you couldrun your car on the starter at about 20 mph!
Maximum draw on a starter (that is not shorted) is close to 350 amps and using the body as a ground has been done for years.
Ground thr battery to the sub frame near the trunk and use a cable #4 or #2 from the frame to the starter ground.
The positive wire has to go to the solenoid in order to connect to the rest of the electrical system. You either run a "0" AWG cable from the rear to the solenoid or you run a "0" AWG cable to your starter. Either way when you run 12V DC 12 feet with a load of 350 amps you have to use BIG cables.

MustangBradley

The 1000 amp figure is referring to the situation when the wire becomes shorted. This is a real concern if a wreck occurs, since the longer the wire, the more chance you have of it becoming damaged. With the soleniod in the trunk, that wire is only live when cranking.

With using the body as the ground, it is true that this is quite common. Many people take the shortcut method and drill a hole in the trunk floor and attach the ground. Just because it is common, and "works" does not make it wise. Yes, you do get a valid ground doing it that way. It is better to run a ground wire of the same size as the positive wire back up to the block.