Electrical help!!

I was having problems with my battery staying charged. I did some research and found that it must be a bad battery. So I bought a battery and put it in. When I did this I blew the 30 amp fuse on the switch. Checked all the wiring, looked good. Replaced fuse and it blew again. The prev. owner had a 13 amp battery in the bike and I replaced it with a 14 amp that Honda put in the bike. I bought the new battery from a friend that had it from new and only used it for 2 starts on his old bike. Could this be the problem, or is it something more involved? I dont even know where to start. Please Help!!!
85 VF700F 31,000 miles.

 

you have a short to ground somewhere in a large, fat wire.

you'll need a volt/ohm meter to sort it out

 

Oh this should be fun to find. Any advice on how to start?

 

This could be many things, first, does it blow the fuse with the key off? Did you try disconecting the R/R to see if that is the cause?

 

If the fuse didn't blow with the old battery I'd suspect the new one. The 13a vs. 14 amp is nothing. It's actually 13 amp hour vs. 14 amp hour. All that means is that the battery can power a 13 (or 14) amp load for an hour without discharging below a certain point. Under a dead short condition ANY battery is very capable of producing several thousand amps for a few thousandths of a second (actually by Ohm's law it would be mega-amps but the internal resistance of the battery plus the internal resistance of whatever is causing the short will limit it somewhat). I've burned the tips off a number of screwdrivers with nothing but a 12v battery.

I'd recommend this:
See if the old battery will take a charge using a battery charger while it's off the bike. Put it back on and see if the fuse blows. If the fuse doesn't blow, even if the battery charge only lasts a few seconds, it's most likely the new battery has an internal short.

My guess is that you are running into the Regulator / Rectifier problem that is so common on some model VFR's. I haven't run into it myself so I don't have any particulars but there are many, many posts about it here. There's a good chance that there is nothing wrong with your battery and it will take and hold a charge off the bike.