First, do you know what a battery cable looks like? Then, do you have an idea of where it is headed from the battery box?? Then, have you looked at the engine to see if it is connected there???
Truely, it is hard for me to understand that anyone cannot find the ground strap. Unless of course you just don't know what it looks like?

I just had my battery out again today, as the negative cable keeps coming loose. Today was the first time that I disonnected the cable from the motor, and yes, that is much easier. Hopefully I have gotten it tightened up good enough now that it will stay that way!

 

I realize this thread is old but do u know why your neg cable keeps coming loose? Mine comes loose about every 800 miles or so and now it arced the neg post so I have to get another battery..... any help would be appreciated !

 

Personally, I would apply the bolt cable end with dielectric grease and use Blue Locktite on it and torque it down.

 

Old thread, but looks like it's being read again, so...

Yes, that ground cable is a pita on an '04 up sporty (not that it isn't on the older ones, just worse). I got a 4" longer one, routed it up the left side of the frame to the battery, so I can just connect it with the battery out, and then slide it in, there's room for the wire in front of the battery as it goes in, so much easier than going through the hole in the back. There are so many wires in that area it's not very noticeable. If engineers had to install/replace their designs, bet a lot of things would be done differently.

 

The main cause is vibration. That and the fact that the threads on the battery terminal are lead and you can't tighten them up that much without stripping the threads. You can try two things to prevent it from loosening though. You can put a star type lock washer on the bolt first before inserting it through the cable lug and threading it into the battery and use some blue locktite on the threads making sure none gets between the terminal and the lug of the cable. You may also want to put some dielectric grease between the star washer and the lug (I hesitate to put in on the side the battery terminal is, because if it get on the threads there it could render the locktite useless).

If the battery was arcing like you have said, you may still be able to save it. First make sure that the lug on the cable does not have any carbon build up on it (most of the arcing is From the battery terminal TO the lug. You may have to grind or sand (with a Dremel tool) or chip/scrap the carbon build up off (with a knife). Since the battery terminal is made of lead you can usually clean it with a small wire brush (use a small wire brush to make sure they don't short across the two terminals).

I have also, in the past, used a small cutting disk on my Dremel tool to cut enough of the backside of the battery terminal to insert a nut in there. Then I can tighten down that bolt as tight as I want and don't have to worry about the threads on the terminal at all (I usually only do this as a last resort after the threads have been stripped by someone who got over zealous about not ever having his bolt come loose again). In the old days of motorcycles, that is the way all batteries used to come. I wish they made them that way still.

Hope this answers your questions.