Positive to Negative Ground

[Jeffs52]

Jeff's 52,
hello all, recently bought a 52,
It is wired for 12 volts positive ground.
My main question is what to change to Negative Ground ?
I am ready to replace all of the wiring and keep the 12 volt gen.
I would like to know what all I need to change besides reversing the coil & amp gauge wires.
I will assume the new wiring harness will already reverse these 2 for me.
What about the starter,?
thanks

 

[tech1]

this can easily be done in 6 steps

1. you have to definatly disconnect the battery!!
2. this might sond funny but it works..reverse the wires on the coil.
3.reverse the wires on the ammeter.
4. Switch the ground cable from the frame to a starter mounting bolt or transmission.
5. reverse the battery cables.
6. double check everything and see what you've done...fire it up!!


Jesse Hazell Chevy Duty Tech.

 

[Bossman]

Jesse, why change the ground from the frame to the starter or transmission? Aren't the frame and engine bonded via the strap on the right side that runs from the frame to the clutch housing?

 

[tech1]

To be honest I don't think it's going to make a difference, but the artice I was reading on this said to change it over.

Jesse Hazell Chevy Duty Tech.

 

[vwnate1]

RE: Ground Cable Attachment Point

It makes a _HUGE_ differance in all cars , all cases .

These things take tremendous amounts of current to operate the starter so always having the battery's ground cable connected to the running gear rather than the frame is wise , it's they way it was designed & built , if you're has a chassis ground . it's been changed . there is an allowable .01 Volt (that's 1/10 th of a volt ) drop allowed per conection anywhere in automotive curcuts .

The lights and so on don;t draw as much current as the starter does .

You can always add a grounding strap from the running gear to the frame and / or the body if you want , this is a good idea too .

You should be using # 1 or # 0 gauge cables on both neg. and pos. sides of the battery , you may have to measure them and order from your FLAPS but they'll inprove starting hot or cold and grealty extend battery and starter life .

Those cheapo # 6 gauge things sold @ Pep Boys are crap and should be tossed out .


BTW : those are the correct instructons for swapping polarity , I wonder what boob made it posative ground and why ? .

-Nate

 

[Bossman]

RE: Ground Cable Attachment Point

I finally bit the bullet on my truck and installed a dual battery system. I couldn't find a standard 6 volt Lead-Acid type battery that had the cranking amps I needed that would also fit in my battery box on the truck, so I took the smaller one I had which was brand new and installed it in the box. I then took the Optima 6 Volt I had purchased which also fit in the battery box and installed that under the seat on the passenger side. I had 2 cables built by my local parts house out of "0" gauge wire with crimped connectors that I additionally soldered. One cable goes to the clutch housing mount where the foot starter actuator is mounted and the other goes directly to the starter along with the original cables from the first battery. Now it spins up and starts like a charm. The only thing you need to be very aware of is that you have to be careful when connecting or disconnecting the positive cables since they both are hot anytime either is connected to a batter or the starter since they are paralleled. You must make sure any positive cable you disconnect from anywhere is wrapped in a shop cloth or otherwise insulated before letting it loose. Otherwise you will see lots of sparks.
The Optima battery is designed so you can lay it on its side without worrying like you would with a conventional battery. The battery sits neatly in the shallow well in the floor pan if you orient the battery terminals pointing towards the driver side of the cab. I used a battery mounting set with an adjustable plastic band that spans from the terminal side of the battery to the bottom of the battery. This keeps the battery from sliding from left to right under the seat and the floor well keeps it from moving fore and aft. I drilled two 3/4" holes through the floor pan just inboard of the frame rails so the cables can be routed along the inside of the frame close to the original cable routes. If you hook it up the way I describe, the generator on the old 6 volt system will charge both batteries and you will have twice the current to crank the starter and run lights. Using complete cables rather than just hooking to the original batter will give you more wire to carry the current to the starter with less drop. It works like a charm. The next thing I plan to do is fabricate a plastic cover from something like acrylic to prevent metal objects I may toss under the seat from shorting the battery terminals.
Its not the cheapest way to go but is a way to keep the 6 volt system and make it more reliable.

 

[vwnate1]

RE: Batt. Cable Safety !

Very good ! .

One thing though : if you always remeber this , you'll never have any sparking no matter what =

The ground cables are the first to remove and the last to connect , this is true on _ANY_ vehicle as it prevents any possability of sparking .

I'd have though the Optima battery alone in the factory battery box would do the trick .

-Nate

 

[Bossman]

RE: Batt. Cable Safety !

You're right about disconnecting the grounds first, but in this case it still doesn't provide all the protection unless you remember to disconnect BOTH ground cables. If either ground cable is hooked up both hot cables can arc if they touch anything metal.
The Optima battery does not quite fit in the battery box unless you place it in on the diagonal. It is about 1/4" to 1/2" too wide. It is possible to shave off the ears at the bottom of the batter so you can place it in "normally", but I figured that the dual batteries would help improve the reliability and since I already had both of them the extra work wasn't that much. The install only took me about an hour of putzing around after I had the cables made.
One other thing, for neatness, the 3/4" holes the cables pass through are that big so I could also use rubber grommets on the feed-throughs to help protect the battery cables from being cut by the metal floor edge.