Battery in trunk question?

[65 fastback]

For those of you with your battery in your trunk, where did you pick up a good ground for your negative battery cable?

Tim

 

[Ronstang]

Weld a nut to the trunk floor....that is all.

 

[BAD67FUN]

I would think a thru hole with nut and bolt could work. For us who don't weld.

 

[65 fastback]

Yea, I'm not sure I want to be welding in the trunk (gas tank's also in the trunk).

Tim

 

[BAD67FUN]

I was looking in the trunk tonight also wondering where to put the battery. My initial concern is that the floor in there isn't parallel to the ground. I just took a quick look, so maybe I'm wrong.

What kit were you looking into? I thought the one Summit offers for $42 looked pretty good.

 

[Ronstang]

If you have holes in you gas tank to let fumes become a danger then I think you need to worry about a new gas tank before relocating the battery.....mig welding on one of the sides of the trunk floor is perfectly safe, and I usually do it when the gas tank is out but I would do it with it in place if it was solid. You can use a thru hole if you want (isn't drilling near the gas tank dangerous then too) but how are you going to tighen it properly? If you do this use a body bolt type of nut (with the serrated edges) so it grips by itself. I prefer the welded nut since there is no question of a good ground since the nut is now part of the car. A little anti-sieze compound and you have a worry free, corrosion free connection.

 

[85GTlover]

If you do this use a body bolt type of nut (with the serrated edges) so it grips by itself. (quote)

A self tapping screw? Is that what you mean?

 

[Ronstang]

No, like the nuts holding the strut braces from the shock tower to the cowl....basically a body nut. They are also used to hold the outer shock towers (with the snubber) to the shock tower....and the monte carlo bar if installed>

 

[D.Hearne]

Just me, but on a unibody style car such as a Mustang, I'd run a separate ground cable back up to the motor, this will give a better ground than a 30 something year old unibody.

 

[67coupe351w]

The kit from summit comes with a large self taping screw to use to bolt the ground strap to your frame rail.

I have that kit and I bolted mine to the baseplate of the rear members of the roll cage.

 

[gp001]

I drilled a hole and welded a bolt in. MY car has a fairly elaborate electrical system and I have no ground issues, even up front. I talked with Mark at MAD Electrical before doing this and he said the body provides a much better ground than running a cable to the front.

 

[Ronstang]

Just me, but on a unibody style car such as a Mustang, I'd run a separate ground cable back up to the motor, this will give a better ground than a 30 something year old unibody.

Not true, every spot weld is another pathway....there is no better ground conduit than a unibody, 40 years old or not.

 

[D.Hearne]

Not true, every spot weld is another pathway....there is no better ground conduit than a unibody, 40 years old or not.

I'd still run a ground cable. 30 year old Unibody or not, Copper is a better conductor than steel.

 

[Ronstang]

I'd still run a ground cable. 30 year old Unibody or not, Copper is a better conductor than steel.

For stereos I agree......HAHAHAHAHA.....but I don't like cables under the car to begin with so one is more than enough for me. I built an 93 EFI street/race car with a battery in the trunk. I grounded the battery to the frame and then ran a 10ga copper ground cable directly to the EEC IV as I felt this was a safe way to do it....but engine is grounded to the frame in the front and uses the unibody as the conduit for the starter and it has never been a problem. But as usual eveyone must do what they feel is right.

 

[fastcoupe68]

Ground it to the body. Period. I also weld a nut to the car and then you have a perfect connection for a ground

 

[vobraman]

can someone post some pic's of the battery mounted in the trunk ?

thanks

 

[BAD67FUN]

great question...

 

[gp001]

can someone post some pic's of the battery mounted in the trunk ?

thanks

Here is my setup. The cable from the solenoid to starter (1/0 gauge) and the cable from the alternator to the battery (4 gauge) are run down the passenger side through the door sill. The bolt for the ground cable is mounted in the inner most trunk area (the area under the package tray) and at the highest point possible.

 

[Opentracker]

I run ours to the bumper bolt.

 

[19stang67]

I removed the old tie down bracket on the passenger side and used that bolt to hold down the gound to the frame rail. The rail has a nut welded to the inside of it that the bolt goes into.