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Discussion Starter #1
Hello. Thinking about putting the battery in the trunk so I have a nice place to put the MSD box. Here are my questions...

1. If the trunk is sealed off from passenger compartment (by aluminum sheet covering package tray, taking place of interior quarter panels and cardboard divider), would I need a sealed battery box?

2. Where can I route the positive battery cable. Since I figured 2 gauge cable would fit under the sill plates (it does), that is where I'm routing it. Now, would it be better to route the cable inside the engine compartment or outside along the fender aprons? Would it be good to protect with cable with added insulation?

3. Where do I put the solenoid. I figure that having 15 feet of hot 2 gauge cable running the length of the car, looking for the easiest path to ground isn't a great thing. If I put the solenoid in the trunk, then a wire still has to be routed for the MSD box (10 gauge). If I leave the Solenoid in its stock location, then I have less wiring work to do, and I can simply use a bulkhead connector to connect all the ignition components and the solenoid together. Is relocating the solenoid worth the effort?

I have done searches about relocating the battery on this forum (lots of info about it) but everytime I thought I had all of the answers, I found more questions. I have a basic idea of what I want to do, but maybe someone out there can offer me a solution or give me some advice I overlooked. THANKS IN ADVANCE!!!

Danny
 
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Danny,
Went through this a while back and heres my opinions.
1. If your trunk is sealed you aren't required to use the box (nhra rules not sure about other events)
2. I wouldn't route the cable inside the cabin for obvious safety reasons.
3. Your right about not wanting 15' of hot wire on all the time. Put the solenoid in the trunk. Remember you will also have to run a wire to the alternator from the trunk mounted kill switch which is required for a trunk mounted battery. The switch must kill battery power and also must shut down the car.

I ended up moving the battery back up front because I couldn't find a good way to run the shutoff switch out the back of the trunk without permanently ruining something.
Micah
 

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Hey,
I just did this about 2 months ago. to my knowledge, if you have an aluminum dividor panel for the passenger compartment, you do not need a sealed battery box to be NHRA legal. (if you don't plan on racing, then you don't have to worry about it at all)

2nd question, mount the battery over the right rear, drill two holes on the frame rail side of the trunk panel underneath the battery (one for ground and one for positive)put a grommet in each, route the cable along the front and rear frame rails with ties. Wrap it in heater hose to protct it from heat, rocks, debris, etc. And for the ngine comp, I routed it up the passenger side into the bay and around the pass shock tower and connected it to the solenoid. Make sure you put a ground strap from the engine block to the front frame rail because otherwise the starter will try to gorund out therough the alternator wiring (ask me how I know) I covered it all in convoluted tuybing and it looks pretty clean.

3rd question. Leave your solenoid there. It's a lot easier to route one big wire as opposed to 5 or 6 of em. You would also have to route the starter wire which would completely negate the purpose of not routing a large wire.
Hope I helped. Happy mustanging
 

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Discussion Starter #4
The thing I like about the solenoid in the trunk is the fact that that thick cable doesn't have current flowing through it except when cranking the engine. What are other benefits of leaving the solenoid alone vs. relocating it?
 

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67 coupe, 69 Sportsroof, 86 hatchback
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Here's a pretty good thread: trunk batteries
I would use a sealed box for a conventional lead-acid battery no matter what the "rules" say. The main reason is that batteries in use produce hydrogen gas and a certain amount of sulfuric acid. Look at just about anybody's original battery tray (or what's left of it) and think about that in your trunk. Consider the safety hazards of a trunk full of hydrogen gas. Not only do you want the battery box sealed, you'll want it vented outside the trunk somewhere. If you want use an Optima or something, you can foget the box, but you still want the battery to be very well secured.
 

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Discussion Starter #6
Yeah, wasn't it hydrogen in the Hindenburg when she blew up in flames over Lakehurst, NJ taking over 30 lives with her? I don't think I want a trunk full of that stuff!!!
 

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I have a slightly different take on it, plus a tip. Yes, mount the battery on the RH side, just inboard of the frame rail. I took a standard battery tray and cut the lower support off, flattened the bottom around a few of the holes. I actually painted it when painting my car, to match the color of the body/trunk. Use the standard Ford battery hold down arrangement. A gel-style battery - optima - is a good idea because it does not produce the boil off fumes that folks are talking about. I use no. 2 welding wire - 15 feet, ran it inside the car - the quarter, through the sill, then down into the rocker and out a hole (with grommet) in the front of the rocker panel (which is behind the fender), ran it along the joint of the cowl, engine apron, then along the frame rail, up over the shock cover, to a Morosso Battery Shut Off switch, for which a fabricated a bracket. The switch is mounted just forward of the shock cover. I drilled a hole jin the apron ust behind the positive post on the solenoid and have the hot wire coming out about 1.5 inches into the engine compartment to bolt onto the solenoid. Be careful with the switch to make sure you don't line it up where the shock tower cover bolts don't make contact with the lugs on the switch. Hey, I got a big spark when the lug arced to the bolt - I now have a rubber cap over the lug. As for the ground, originally I ran a ground to the frame rail, but then I developed hard starting problems. Ended up running another 15 feet of No. 2 welding cable under the car and directly to the grounding bolt on the engine block. Problem solved. Until I did that, I had to put a jumper cable running between my exhaust tip and the ground post on the battery. Pretty funny looking but it worked.

I believe it is Flaming River that makes a very cool battery shut off swtich. It mounts underneath the rear of the car and has a long handle with a t at the end. By using this switch, you don't mess up your car's taillight panel by bolting something on there. It's tucked away out of sight, pretty much. I like having a battery switch cause I can use it as a power source for things. Oh, yes, if you can find an old worn out autolite red-top battery, you can cut the bottom off then break out the lead plates and make it nice and hollow. Mount your MSD box on your stock battery tray under the hood, then place the "battery" over it. You can actually hook up battery cables to it and then use the underside of the posts as power and ground sources for the MSD box. Nice way to hide it away and make your car look "stock".

Good luck.
 
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