I kept just my battery in the trunk. I run a 1 gauge set of cables from the battery, one short to rear ground, second long that runs to the solenoid up in the fenderwell. At the solenoid, I have the hi torq starter hooked up to it, and for additional power feed, I run a 4 gauge cable from the battery. Side to a distribution block. The block house 4 30 amp fuses that power the msd box, electric fan relay, fog light relay, and fuel pump relay.
Another 4 gauge cable with a 175amp max fuse runs from the 130 amp alternator over to the distribution block to charge the battery through there.
I had this exact setup on my fox for years, I transplanted it into the 66. Works great for me.
I prefer to run a large power cable from the battery to the solenoid up front instead of a long cable to the starter from a rear mounted solenoid... that's just me tho...

 

I prefer to run a large power cable from the battery to the solenoid up front instead of a long cable to the starter from a rear mounted solenoid... that's just me tho...

Actually I believe I took close to 5 feet of cable (and weight) out of the starter loop by putting the battery and solenoid in the trunk vs running a hot wire all the way to the solenoid and back to the starter. 1 foot battery to solenoid mounted on the fender side of the trunk hinge mount, then a ~4-5' run under the car from solenoid direct to starter. Definitely saw a big improvement in starter performance, I did it your way originally till I got smart and moved the solenoid to eliminate the hot wire direct from the battery.

Ran a #8 (I think) fused power wire to a terminal block next to the radiator just above the MSD. I have a big fuse in the trunk on that line and two fuses up by the terminal block, one for the EPAS and the other for the house.

Don't forget to put a fusable link on the Alternator GM style. If you have a major short with the engine running all the fuses in the car can blow but the alternator will continue to fry things till the engine dies.

 

Here is my adventure:

http://forums.vintage-mustang.com/mod-custom-forum/993930-battery-trunk-blowing-fuses.html

 

You can fuse the wire instead of moving the solenoid. Use an automotive mega fuse and you won't have any dramas. They are slow blow fuses and you won't blow it under normal starting procedures ie not cranking the car for 2 minutes while it is in gear(if you do that you don't deserve a car anyway ha ah)
I have a 200amp auto mega fuse on mine. It makes the whole install a lot cleaner while still providing a safe fused protection. I purchased mine in australia, however this is an example of what I am talking about. Most auto electrical or electrical stores should have them and the holders.
Littelfuse MEG250XP MEGA Slo-Blo Automotive Bolt-Down Fuse | eBay

A pic of my setup is below(the smaller wire is for the stereo amp). The cable runs from the box into the fuse holder then back down into the wheel well and through the rockers. I mounted the fuse on top for ease of serviceability as well as making it very easy to disconnect the battery without having to take off the battery lid every time.

What ever you decide to do though, make sure it's either fused or at a minimum not hot all the time. Yes, most people get away with it. But if you haven't seen how quickly a short circuited power cable burns, look around on the net. You'll be roasting marshmallows on the side of the road.

 

I've done this. I basically didn't want an unfused thick live cable running the length of car with high amperage.

I essentially used a 1/0 welding cable to connect the solenoid to the starter. From my reading, you really can't fuse a starter cable. I found a starter that only required one wire to make it work so I used that.

For power distribution, I used an 8 gauge wire to run up to a power distribution point that I mounted on the passenger side kick panel. From there, I power the main fuse panel, connect the alternator feed, convertible top, etc. That 8 gauge wire is fused with a 175 amp fuse.

I've never had any issues with this setup.

Below is a pic of my setup.

Thanks,
-Shannon

 

Your design looks great. Well thought out. Did you run separate fused supplies to your alternator and power distribution for your car?. 175 amp protection seems to be a lot for the main harness supply.

 

My approach was similar to Shannons.

I just did this on my 70, however, I much went further than you need to go, since I needed to meet NHRA rules with a cutoff switch. I took it to the point making sure absolutely all battery power does not leave the trunk when the disconnect switch is pushed, along with stopping the engine.

I personally did not like the idea of fusing the BIG starter wire keeping it always HOT so I switched it.

Here is a summary but see my build thread here for all of the details: http://forums.vintage-mustang.com/build-forum/725585-1970-mach-1-460-sbf-boss-build-thread-18.html


1. Disconnect Switch was used to kill the power to the trunk starter solenoid and a continuous relay for any other power- see below.

2. A Ford relay is used for the big starter cable (1/0 welding cable) and that cable is only HOT when cranking. After looking at a number of paths to run this cable, under the car was not possible with out lots of drilling and wandering around due to the frame reinforcements and outriggers. The cable runs from the trunk, inside over the right wheel well where it enters the interior behind the door, then along the bottom of the door sill, finally exiting through the floor kick area and right to the starter. This wire is encased in nylon braid, and any areas where there is the possibility of rubbing, grommets AND fiberglass sheathing is used, such as where it passes through the floor and where the cable enters the interior. The small section (about 14") from the floor to the starter is encased in DEI ultra sheath high temp tubing to protect it from the headers, and a small bracket holds it close to the block.

3. A continuous relay is used to switch all main power from the trunk as well as the alternator charge line. It is turned on/off with the kill switch.

4. A good ground is key. In the trunk there is a ground stud welded to the frame and roll bar plate as a common point for the battery and an additional dedicated ground cable that goes to a stud in the engine bay.

5. Like the starter cable, all wires from the trunk are all encased in flexible nylon braid and ran inside the door sill tray.

6. For the MSD box power I ran a separate 8GA wire, to a lug in the engine bay, and a second 8AWG to another stud for the main power.

7. There is a Maxi fuse for the MSD and Main PWR harness in the trunk, and being overly cautious, I also have another maxi fuse in the engine bay on the alternator charge wire, so that link is protected at both power sources (BAT and ALT).

Hope this helps

 

Be cautious with fuse sizing and wire ga/length. see attached chart.

 

Wow, thanks for all the quick responses!
I am more comfortable with the starter solenoid in the truck for live wire reasons and, in theory, the starter cable should not be fused.
Plan on upgrading to an EFI engine in near future and read that a solenoid with suppression diodes like those in 1990's EFI cars and truck should be used. Are they a direct swap? They look to have a different design (no connection for #262) so want to clarify the wiring. My question relates to wires #32 and #262 from ignition switch.
Here is soleniod:
https://www.amazon.com/Motorcraft-S...KY/ref=sr_1_2?ie=UTF8&qid=1488986504&sr=8-2&keywords=1995+ford+starter+solenoid

Refer to attached diagram for wires. #262 looks to have a resistor wire right before ignition switch and only hot when cranking, what is it's function? I assume the newer style solenoid only has a connection for #32 so what to be done with #262?

 

Well like I said you CAN fuse it, that's how I run it and how a lot of other people run it too, and I have cranked my starter A LOT over the last few months testing certain things.
Remember, if you move the starter solenoid in the trunk, then you need to run another power cable to the front for your main power feed. So you now have two cables you need to route instead of one, plus your start signal wire. Just starts to get messy for the sake of it.

Anyway up to you, the starter solenoid in the trunk is still a good solution. I just wish people would stop saying "you can't fuse the starter cable" because that is just not true.

 

A lot of great information. Will help me and my wiring

Sent from my SAMSUNG-SM-G930A using Tapatalk

 

If I was to do a rear battery installation I would start by running straight battery power into the passenger footwell area with an eyelet connected to a "power distribution" block designed for high current. From there setting up the main starter power then basic fusible link feeds to the alternator, fuse box, relay center including a starter relay would be very much simplified.

 

Studied the wiring diagram a bit and confirmed under dash locations of #32 and #262. From ignition switch #32 runs through the neutral start switch on tranny then off to starter solenoid. Will splice into #32 after NSS. #262 provides a "boost" voltage to coil on cranking to help generate a powerful spark and basically runs straight to coil. It connects into 16A resistance wire from ignition switch and 16B which goes to coil. Still don't understand why 16A is resistance wire, anyone have the answer? Going to splice into #262 route to right post of starter switch.

I know it's an extra live wire but decided to run a constant 4 gauge hot to under dash power post then off to engine bay with another power post for power requirements of those areas. When all amp demand has been totaled will fuse accordingly. Should not be over 100 amps since stereo amp is in trunk, much lower than that required for starter. I am stuck on not wanting a high amp live wire running through cabin. I understand using a fuse solution but the mega fuses are slow burn and can still let a fire start if wire gets grounded. Will a lower amp fused live wire present the same fire risk, :shrug:. Fan and head light relays should make up most of draw...
Here is the power posts I am going to use.
https://www.amazon.com/gp/product/B000K2NZ1Y/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1

Again, thanks for all the input from everyone.

 

I understand using a fuse solution but the mega fuses are slow burn and can still let a fire start if wire gets grounded.

A short will blow the mega fuses right away. They are slow blow in reference to load %. For eg, at 200% load it may take 5 seconds and at 300% it may take 2 seconds and so on(this is not the actual data just made up figures, but that's how they work). A 250amp mega fuse on 0 or 00 cable should blow instantly if the cable is shorted.

 

I picked up most of my terminals and buss bars here. A good selection and prices are better than other places. Key is a min $25 order so think about everything you will need and get it at once.

https://www.vtewarehouse.com/html/thank_you.php

For the single terminals I went with their larger 771 series with 3/8 terminal.
https://www.vtewarehouse.com/content/electromech/PDP/html/770Series/770Series.php

and use good insulators. I used them on all hot terminals in the trunk and engine bay, including on the trunk solnoid.
https://www.vtewarehouse.com/content/termins/200Series/200Series.php

 

Found the answer to my 16A resistor wire question.

"The resistor is required on all points or Duraspark systems. It's also called a "ballast" and its job is to maintain roughly the same voltage at the coil regardless if the key is in START or RUN. In START, the coil is powered directly off 12 volts through the I terminal of the solenoid. But because the starter pulls the battery voltage down during cranking, the voltage at the coil falls below 12 in START. Without the ballast resistor in the RUN circuit, the voltage at the coil would jump to full voltage and be drastically different in RUN than in START.

The resistor wire drops the voltage at the coil to 6 to 7 volts in RUN and both the coil and ignition module (or points) are designed to operate with this reduced primary current. As MH said, eliminating the resistor limits the lifetime of the coil. In lieu of the factory-style resistor wire that would have been part of the original wiring harness, you can install a stand-alone power resistor (available from the parts store) under the hood. You want something close to 1.3 to 1.4 ohms."

 

Here is my set up. 1/0 welding cable to the starter, 4 gauge 180 amp protected to a distribution box where the battery used to be. Done with AAW complete 68 kit.
All wires inside the car and a "dewired" engine bay.

 

Do you have more pics. I'm trying to build my list to purchase parts for my rewire

Sent from my SAMSUNG-SM-G930A using Tapatalk

 

I'd be interested to know more about how you 'dewired' the engine bay. I'm going to be starting the wiring work on my car towards the tail end of April and wanting to keep the bay as clean as possible. Along with the battery in the trunk.

 

I routed as many of the O/E engine bay wires as I could under the front fenders and all of the wiring to the trunk mounted battery is inside the car.
The car has a complete AAW rewire kit in it so the hidden wires were a snap.
Instead of me reposting the photos do a search on the "mod and custom" forum you will find the pictures I posted on those mods.