Battery Ground Question

[440roadrunner]

..................All Those Welds That Will Not Conduct Currrent Correctly!....................Terry

This is not really the issue. I think the issue is rather, actually being able to make decent body connections. "Back when" guys started doing this sort of thing, we didn't have the dual bolt or even 4 bolt ground eyes like the Burndy connectors:

I've often also thought that doing something like silver brazing a copper pad into the truck to provide more surface area would help, with a matching one up front. Anyone that thinks "their welds" won't carry enough current needs to worry about the unibody itself coming apart!!!!

 

[RustyRatRod]

ISeems John Has A Problem With Chrysler's Unibody And All Those Welds That Will Not Conduct Currrent Correctly!

I can tell you EXACTLY what problem that is. It's like running a dribble of water through a schedule 40 sewer pipe. The size of the whole car cuts the current way down, similar to running too BIG a cable. I don't think it's that he doesn't trust the car to conduct, I think it's that he KNOWS the car is to BIG a conductor. The current needs to be held in the confines of the proper size cable in order for all of it to reach it's destination. I hope that made sense.

- - - Updated - - -

It's cool. I didn't think you were takin issue. I just wanted to make sure we were on the same page.

Rusty, I respect your opinion and was not taking issue. Of course you have to ground the engine to the body just like the factory did and I consider that as a given. I was just stating the factory ran a large negative cable from the battery to the block in addition to the engine to body and battery to body grounds. As I understood the question, the owner does not have a negative cable between the battery and engine and that is what I am commenting about. My opinion is he does need a cable between the battery and the block, in addition to the battery to body and block to body grounds.

 

[chattacuda]

cool, we are on the same page.

 

[RustyRatRod]

I thunk we wuz. lol

cool, we are on the same page.

 

[440roadrunner]

I can tell you EXACTLY what problem that is. It's like running a dribble of water through a schedule 40 sewer pipe. The size of the whole car cuts the current way down, similar to running too BIG a cable. I don't think it's that he doesn't trust the car to conduct, I think it's that he KNOWS the car is to BIG a conductor. The current needs to be held in the confines of the proper size cable in order for all of it to reach it's destination. I hope that made sense.

.

Please Rusty PLEAUAUZZZZZZZ

This is NOT how current through a conductor works.

RESISTANCE of a conductor depends on

material the conductor is made of, IE copper, aluminum, is better than steel for the same size. Some materials like copper have less R, some like steel have more R

whether it's solid or stranded, IE (with DC, not AC) the total cross sectional area) The larger the area, the lower the R

and the length of the conductor. The shorter the conductor, the lower the R


http://en.wikipedia.org/wiki/Electrical_resistance_and_conductance

"An object of uniform cross section has a resistance proportional to its resistivity and length and inversely proportional to its cross-sectional area"


The important part of that statement is "cross sectional area." and "inversely proportional"

What this simply means, SIMPLY is that the larger a cable is, the lower it's resistance. There is no such thing as "too large" a cable, or current somehow getting lost or drying up because it's too big.

The floor of a unibody is not QUITE that simple, because of the way the cable must connect, and it certainly is not exactly "uniform."

 

[RustyRatRod]

Whatever dude.

 

[Jeremiah]

Wow...there is some crack smoking going on in this post.

All you need to do is run a big positive wire to the main lug on the starter relay and run the negative battery cable to the frame below the battery. Make sure the metal is cleaned and use some no-ox or similar conductive grease to ensure longevity. In the engine bay run a ground from the body to the engine and from the engine to the k-frame. Also make sure to ground individual components aka line lock, ignition ECU, etc. to a common ground that is connected to both the engine and the body. I have been running around on the street for TEN YEARS with a MSD 7AL2, drag radials, roller cam, 3.5" front wheels, a pro shifted 4-speed, and a battery in the trunk. All of the myths surrounding the above listed parts are complete BS so unless you have direct experience in this stuff the "I heard", "someone smarter than me told me so", etc. is not admissible in the court of gear heads. <gavel slams on the desk> As always, IMHO. : )