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If it were a car, that's a really big jump,,, I'd say you may have a bad spot on your starter or a problem with the starter solenoid. They are the only things I can think of that would be able to draw down all the power repeatedly without blowing some fuse.
 
i had just taken the battery off trickle charger when i read the volts. that reading was with the switch off. 13.7 then turned switch on read volt meter at 12.7 then hit start button dropped to 3.8 one click at starter continued to watch volt meter switch still on slowly climb back to 12.7 then turned switch off volt meter went back to 13.7
 
tdj45 said:
slowly climb back to 12.7 then turned switch off volt meter went back to 13.7
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**Very important question**
Are you are reading ALL these voltages (13.70 V,,, 12.70 V,,, 3.80 V) DIRECTLY at the Battery POSTS and NOT at a fuse or some other point (engine block & fuse) or between the starter and engine block?

If you are reading these voltages DIRECTLY AT THE BATTERY POSTS,, using a HANDHELD multimeter (not any built in gauge on your bike),,, your problem (or at least 1 of them) is a bad battery.
If you are reading these voltages off some fuse, the starter or the engine block, Stop & back up. The battery may not be at fault.

You can take a perfectly good fully charged battery and pull it down to 3.80 volts using a 500 amp load. But the battery post voltage would never float back up to 13.70 volts when the load was removed. That is impossible. If the battery was good, the voltage would float back up to something like 12.25 or there about.

The nominal voltage PER CELL of a lead/acid glass mat battery is 2.1 volts. Therefore the nominal voltage at the battery should never exceed ~12.6 to 12.7 AFTER you take off the surface charge from the plates. In order to pull a good fully charged battery to 4 volts would require a huge load which in turn would strip the surface charge right off the battery.

I am also assuming that you are Not using some cobalt-ion or lithium-ion battery that has a nominal cell voltage of something other than 2.1 volts. Please don't tell me you have a Toyota Prius battery in your bike as an experiment.:)
 
getting all readings from battery post. bought the battery at the harley dealership. also had it load tested read full charge and 347 cold cranking amps.
 
tdj45 said:
also had it load tested read full charge and 347 cold cranking amps.
Click to expand...

So if I understand the sequence of events,,

You have a Genuine Harley Davidson battery installed in the bike. You hook it up to a charger and let it charge overnight. You disconnect the charger and connect a multimeter across the battery terminal posts (battery POSTS not battery cable terminals).. Your meter now reads 13.70 volts D.C.
The battery charger is now disconnected and will remain disconnected for the remainder of test.

While watching your voltmeter, you turn on the ignition key (the headlight is now on and bright) and you see the voltmeter decline to 12.70 volts DC. You now hit the start button (engine crank, starter) and you see the voltmeter read 3.70 (three point seven zero) volts DC. You hold the button in for a couple of seconds and then release the starter button. The meter starts a slow climb back to 12.7 volts. You now turn off the ignition switch and the voltmeter continues to climb back up to 13.70 volts and remains there.

If this is true, you either have a bad battery or a bad multimeter.

Wish I could be there. This I would like to see. :)
I have this bad feeling about the way you battery may have been tested. Something about this problem that is very simple and easy is just not right.
 
going to buy a new muitimeter 2-day will post the results thanks for eveyones help

with new multimeter got same readings. here's whats got me stumped. 1st i removed trickle charge. 2nd i turned switch on and no power at all and then after about 5-seconds power slowly comes on to about half power. 3rd i turned switch to acc. and gauges lite up normal. 4th i turned switch back to ignition and had full power, head lite brite. 5th i hit start and same results as always.
 
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Have you tried jumping the contacts in the ignition switch yet? It sounds like it could be a bad switch.
 
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