Ground wire on fire/melting

I'm trying to get my 225 fired up and my ground wire melted and cought fire.What would do this.Ground goes to negetive right!

 

Yes, ground is negative on all US cars.

Which ground wire? The only way a wire can melt is if you have too much current running through it. If the ground wire is the smallest wire in the circuit, it will melt first.

When starting, most of the current should flow back to the battery through the negative battery cable. That should be tightly connected to the engine block. If not, current will seek an alternate route, maybe from your fender through the ground wire to the negative battery terminal.

 

Yup, my first place to look. A bad connection is a "bottleneck" which is similar to a much smaller diameter wire. The connection can't handle the current flowing through it, and eventually things get too hot and all the magic smoke comes out. Can't run the Jeep without the magic smoke ya know.....

 

One of my electronics profs used the exact same analogy about ICs. R)

 

On all Jeeps, but don't go telling people that there are not any positive ground US cars - there are plenty

 

Actually, current flows from positive to negative. Electrons, which are the charge carriers, flow from negative to positive. However, everybody nowadays since the advent of semiconductors recognizes current as the flow of positive carriers. This is called the "conventional current flow". Older texts, especially those whose main purpose was to give a technician an intuitive feel for electricitiy, used "electron current flow".

If you think it is confusing, wait until you get into semiconductor physics, where you have electrons, and "holes", which are the lack of electron. However, holes have mass and can collide with each other.

Sorry to nit pick. We have Ben Franklin to blame for all of this by assigning a negative charge to the electron.

 

I was useing a boat battery.I think it was 12V.It was the ground going to the fire wall.The ground is/was a heavy copper braid rope.I made sure nothing was loose and it did the same.Would a 12V boat battery be too much.

 

Is the engine block grounded well?

 

I'm going to take it off and put new washer in.Here is the battery I was useing,Stowaway Tournament type ST24MS000 with twin stainless marine terminals,1,000 marine cranking 800 cold cranking 115 reserve capacity.

 

That is a body ground not a battery ground. You have a situation of "path of least resistance" Nature finds a way and if went through your grounding strap. Something is wrong with your negative cable I suspect

Either that or the if that strap goes to a grounding bolt and continues to the battery, the strap was degraded and simply burned up.

 

Warning - this is a response to the topic hijack...

Actually whoever said that current goes from negative to postive is right.

The US Navy spent a lot of money teaching me this stuff (thank your very much - I used this skill all my life!).

If you remember back to the vacuum tube days. Most of you don't. Hey there are a ton of people who have never seen a vacuum tube.

The voltage applied to the anode was usually in the +200 VDC range (sometimes a lot more).

The current went from cathode to anode controlled by a small negative signal on the grid(s).

Current never went from anode (plate) to cathode unless something was short circuited, and usually something was on fire, so one was't measuring plate voltages at the time.

Same for transistors whether they were PNP or NPN.

Same for diodes and zeners.

Reasonable people can disagree, but there are times when there is a right answer.

 

lets move this to off topic

http://www.earlycj5.com/forums/showthread.php?t=13191

 

my 42 willys is positive ground

 

So is my 1964 Tuxedo Park 12v 225 a negive battery ground/body ground?Do you guys think I ruind the battery?It's not mine!!!!FATHERS!!!!KNEE DEEP IN SH**!!!!

 

Does anyone know anything about MARINE (Stowaway brand) batterys?

 

I don't think the battery is the problem, if that is what you're worried about. Make sure you have a good, solid connection from the engine block to the battery. I would guess that yours is bad or missing, and the engine and starter are getting their ground from the body. That is why that wire is melting.

 

The battery is not the problem and you probably didn't hurt it. The bigger the better (as long as it's 12V). You have a bad ground going to the engine block. Go get a couple new cables. One needs to be run right from the negative post on the battery to the engine block. Another needs to be run from the firewall to the engine block. Make sure you clean everything up really well when you hook up the new cables or you could still have problems.

Response to the OT: Current does in fact flow from negative to positive. HOWEVER, Sternbal is correct in his statement about it flowing from pos to neg. This is what is commonly taught and accepted today. Don't ask me why, but it is. I just graduated from an Industrial Technology program and in all my physics and electromechanics courses we were taught the pos to neg theory. It's all just theoretical anyway