Topic: Battery draining

[ddrink]

Having a problem with my battery draining.  If I leave the battery hooked up over night, the next morning it's dead.  To start my trouble shooting, I unhooked everything that could be drawing power. Then started hooking back up one at a time, and testing afterwards.  Volts stayed put until I hooked up the white wire from the regulator.  Once connected I could watch the volts drop on the meter.  I just bought this regulator from Oregon Motorcycle Parts.  Does this sound like a got a bum regulator, or should I be looking else where?

[ddrink]

Sorry got my colors mixed up, its the black wire, not the white.  Also I did check for any bare spots in the wire, found one, replaced the wire, this slowed the draw a little but did not cure it.

[bryanj]

That "live" black should only be live when the ignition is switched on! If you built your own loom and didnt notice that theres youre problem

[oldbiker]

When the black wire is live, the coils and the alternator field are drawing current and this will be enough to flatten your battery overnight. As bryanj says this black wire should only be live when the ignition is switched on so either your switch is faulty or you have wired your bike wrongly.

[broken]

I'd go over all the accessible wiring and switches for faults of any sort since that's usually the easiest, as well go get yourself a Battery Tender so you can at least keep it charged while you figure things out.

bro`ken

[sixshooter]

on my 1972 750 4,i was setting in the house on a rainy night and saw my headlights come on.well i thought someone was trying to borrow my bike.turns out the swithch shorted due to water,the engine would even start.for a temp fix i put a toggle switch in series with the fuse (72 750 only has 1) after replaceing the switch i left the toggle in place.neatly hid of course but could come in handy sometimes as matter of fact i have gotten in the habit of useing it whenever i leave my bike unattended for any length of time.

[ddrink]

I think I may have found my problem, did some more testing tonight after work.  I unhooked the harness going to the altenator, the power draw stopped.  I took this one step further, I pluged the harness back in, but unhooked the field coil, tested off the battery and there was no power draw.  To double check I pluged the coil back in and the draw was back.  Has anyone heard of a coil causing this before?  And does anyone know where to get a new one cheap?

[TwoTired]

The coil develops the magetic field in the alternator that allows it to generate power.  With the ignition on and the engine at low speed, full power must be sent to the field coil.  This power (votlage level) is only reduced to the field coil by the regulator when the regulator senses the battery voltage above 14.5 volts or so.  With the engine stopped or at low speed the battery will not have this high a voltage, the regulator thinks the battery needs charging and tells the alternator to put out as much power as it can.  Yes, this can drain the battery if the engine isn't turning fast enough.

The regulator power (black wire) should be switched on and off with the ignition switch.  This will prevent the the field coil from totally draining power from the battery when the bike is not in operation.

Cheers,

[bryanj]

Like I said that black wire, in fact ALL black wires, should be non live when the ignition switch is turned off

[ddrink]

Thanks to everyone for help on this one.  As always you were right, it was a wiring fupar on my part, that problem is now corrected.  But ofcourse I came across another issue I need to address.  With the main harness coming from the altenator unhooked the bike runs and idles like a dream, however, once I plug the harness back in, it will not idle.  I have double and triple check my wiring and everything seems to be correct.  And the altenator is putting out good power 14.46v over 1500rpms and 14.02v at 1000rpms.  Is this sounding like another faulty wiring job on my part?  any input would be appreciated.

[oldbiker]

When you unplug your alternator wiring, you reduce the load on the motor. (180watts equals about 1/4 horsepower)  This may just upset the idle setting. So maybe your carb setting is not quite right.