Rx7 negative cable arking.
 

Hi I finally found an Rx7 with little rust the only problem is that apparently the negative battery cable arcs on the negative battery post. I have not messed with it since I bought it a day ago I'll post the Craigslist ad that describes the problem if anyone know anything please help me thank you. If you need a picture of anything just ask.

Arcing would tend to lead to a bad connection/cable/ends. I would just buy a new ground cable. Not sure about the second gen, but the first gen has a ground spot on the shock tower before going to the starter.

ask the Dude if he is trying to put the Cable with the Yellow stripe on the Positive..
As That is WRONG...the STRIPED CABLE GOES ON NEGATIVE..

Ah ok I guess I'll try that out the ground cable does look sketchy I'll provide a picture of it.

The cables seem to be connected correctly... The cables that go to the battery don't have any indication of the positive and negative. But I figured that the negative cable is the one with the ground sticking out right?

2 things.
The cable connectors are different sizes and match the posts of the battery.They are made that way so you should really screw it up when connecting the battery (if your cables are the same color)
Now Mazda made the Negative STOCK cable with a yellow Stripe on the FC so that you could distinguish the Pos and Neg.
Some ways of Telling if you have the right wires is to OHM the wires out.With the cables Disconnected you should get ZERO from NEG to Car chassis and also ZERO from Alternator(single post terminal on alt) to Positive cable connector.

sure looks like your battery is backwards. that seems to be a negative stamp on your battery that is nearest the engine, which would be wrong.

Ok I'll test that out later today but if the cables where connected correctly what else could be causing my problem bad ground somewhere?

You can't really tell from the picture my bad on my part but The negative is the farthest away from the engine the positive is the nearest. Any ideas on what else it could be?

Check wiring to the alternator.

The connections to the alternator look fine the rubber sleeve is cracked but other than that everything looks fine.

How much of an arc is it? Is it just a quick snap? If so thats pretty normal to have some arc when you hook a battery up

I have not seen the arc myself I am too scared to connect the engine and turn the key. Apparently if I start the car the main fuse will blow

If the fuse blows then you have a massive current drain or a path to ground from a positive wire.

I see so I would need to go through the whole harness and try to find the path to ground from the positive. I have another question is there such thing as a starter harness? Apparently, that might be my problem. I am truly clueless on the electrical system.

The starter has the positive and negative from the battery and also a 12v trigger voltage.

I would start by disconnecting the positive battery and negative cables from the battery and starter and checking resistance to ground for both cables. Checking resistance to ground would be putting the negative ohm meter probe to a known ground point and using the positive to check the other wires.

Ok thank you I'll go do that and keep you informed. Thanks again

the only reason the main fuse would blow is if your alternator charge wire was grounded or the battery is reversed.

and yeah, i zoomed in on the picture and the terminal closest to the engine does not appear to have a +, but sure seems to be a -. maybe there is some camera trickery involved, but sure doesn't appear to be.

Ok I'll double check sorry for the late reply I at was at work.

Update!
 

I found out what the problem was. There was a ground wire connected to the starter.... a small part of the wiring harness was fried.