New battery goes flat in two hours.

[helomech]

Well, the battle I've been fighting with my electrical system since last fall continues. I replaced the Battery, main ground cables and rectifier. I still can't seem to get any life out of the battery. I charge it up with the battery tender, I starts fine, Charges fine while it's running, and starts right back up if I don't wait too long, but if I leave it for a couple of hours, I can barely get the engine to turn over once. I measured the resistance of the entire system between the battery cables with the battery disconnected and key off and read 47 kohms. Is this normal and if not, what might be causing the draw? I haven't yet replaced the cable between the starter and the solenoid yet, I intend to, but I don't think that is the problem. I'm getting real tired of watching everyone else's bike through the windshield of my suburban while mine sits in my garage because I don't trust it to start if I stop anywhere.

[GeorgeS]

1900 Hours, standby, I will go measure the resistance on mine

[ibsaw]

i,m no expert on bikes but i do kno that 47 kohms or 47,000 ohms is quite a load and would drain any battery in little time

[GeorgeS]

On my 89, Removed Pos. battery cable, measured resistance of main cable to ground, and Accessory cable that goes to the main 40 Amp Fuse.

---- Resistance reading is Infinate, on my Ohm meter, ( digital )

No connection to ground.

 

Check. Are there ANY AFTERMARKET ACCESORIES INSTALLED ON THE BIKE, REMOVE FUSE TO ANY OF THIS STUFF!!! Horns, Extra running lights, trailer light system, WHATEVER IT IS, ESPECIALLY, IF NO FUSE HAS BEEN INSTALLED FOR THE NEW STUFF!!! DISCONNECT THE WIREING TO ANYTHING THAT HAS BEEN ADDED TO THE BIKE !!!!! Has anybody added a radio, CB Stero amp, Anything!! disconnect it !!!!!!

 

THEN----- Now Recheck for the 47K resistance.

 

If its still there, then-----

 

Remove all the STOCK FACTORY fuse's in the fuse holder, take resistance reading.

Does it change ?? If, its Infinate now, ( Open ) start reinstalling fuse's one at a time, untill you see your 47K of resistance. Now troubleshoot that circuit.

 

If Not, open up the Main fuse holder, remove fuse, take reading from the fuse output to the fuse block. It should be Infinate.

 

Now with battery installed, and all fuses removed ( includeing the main fuse ) your battery is still connected to the Start Solinoid !! And the Start cut off relay and to the Start Switch, One of these three Items might have the 47K Resistance to ground.

 

--- NEXT REMOVE IN ORDER OF 1. cable to start switch.

 

---------------------------------2. Start cut off Relay

 

----------------------------------3. Heavy battery cable to Start Solinoid.

 

However haveing said all this, I suspect some added accessories are the culprit.

[helomech]

I had tried pulling all of the fuses but still got the 47k-ohms I've also removed all of the accessory lighting, (I kind of like the clean look). The only thing I can think of that is hot wired all the time is the clock, but that should be a very large resistance value. I know 47k-ohms are a very common value in electronics but I figure the clock should be much higher resistance with a insignificant voltage drop across it. Right now I have no radio installed, the cigarette lighter is disconnected, the CLASS is disconnected(inoperative, need a replacement unit or parts for it), I guess I'll have to check the solenoid tomorrow. Drat, gotta remove the dang fairing again.....

[GeorgeS]

See Circuit from battery, goes thru solinoid, to the start cut off relay, and from there to the start switch.

 

---- this part of circuit, is With the Ignition OFF. -----

 

Pull the L/W ( blue / white ) wire at solinoid, and read resistanc thru the cut off relay and start switch to ground. you might see the 47K here.

 

Its also, possible, there is Carbon build up on the Main contacts in the Start solinoid, makeing a high resistance circuit thru the starter motor.

[Condor]

Am i missing something here??? I could have sworn ohms was a measurement of resistence over a length of conductor, not a measurement of current in volts or consumption in amps??? I'm not sure I follow why a resistence would cause a battery to go dead?? Remember i am getting old.

[GeorgeS]

Jack, If I understand him correctly, he is saying that with + cable disconected from battery, and then reading resistance from + cable to ground he is seeing 47,000 ohms. Which is a High Resistance short to ground, with the Ing. SWitch Off. If, so this would drain the battery.

 

--- I asked him to remove all fuses, and then check for the high Res. short. he claimes he allready did that.

 

--- I suspect sombody has added some accesories to the bike, which may not be fused.

 

--- Possibly he has a wire shorting, ( worn thru ) to the frame somplace.

 

---- With all fuse's remove, the Solinoid is still hooked to battery, and thru the solinoid actuator coil, and then to the Start Cut off relay, and then to the Start Switch. There might still be a problem in this circuit, because its not fused.

 

Anyway, if you have any ideas.

 

One more thing, he said he has a new battery, he mentioned charging it with a Trickel charger, now I am wondering if this new battery has ever been Initially charged at 3 to 4 amps for several hours. ???

 

Or, is the fluid level correct, and bring to full charge, maby thats not been done.

[Condor]

Anyway, if you have any ideas. .

 

George, I see where you're going. You're checking for continuity between the hot lead and any ground in order to find a short. OK, the light bulb just went on.

[concours]

Set your meter to "milliamps"..... then put it between the positive terminal and positive cable. That will tell you true current draw.... better yet, start with the meter on "amps" because 2 hours battery kill time is pretty damned stout... Then proceed with the seperation/isolation procedure mentioned above. Remember to not turn on any high current accessories or you'll pop the fuse in the meter.... (10A in a Fluke 77)

[Guest timshosvt]

My brand new battery didn't go dead, but it did get weak in a few hours when I punched the little rubber buttons on the clock through the dash panel, causing it to continue to try to set the time. It looked fine with key off, but numbers cycled by with key on. Took the dash apart, rehabilitated the buttons with pb blaster, put them back in...clock works fine and battery has been fine, as well. In my instance, the clock killed my battery.

[Al Bates]

Do a battery Drain test, If it pass's the battery drain test it could be a starter resistance problem.

 

The AB Battery Drain Test.

Take a 12 volt test light. Make sure that the battery is fully charged. Make sure that everything on the bike is turn off. Make sure that the test light is working. Test the test light by putting one end on the + side of the battery and the other end on the - side of the battery. The light should be on. If not the test light is faulty.

 

Disconnect the + side of the battery terminal from the battery.

 

Connect one end of the test light to the + side of the battery.

 

Connect the other end of the test light to the bikes + battery terminal.

 

Now the test light should be connected in series. Between the + side of the battery and the + side of the bike battery terminal.

 

Now if everything is turn off on the bike there should be NO light in the test light.

 

If there is a light there is a drain on the battery. Something is draining the battery. Start pulling fuses until the light gos out. It's in that system.

 

To test this theory, if there is no light in the test light turn on something, like the ignition. The test light will glow, the brighter the light the more the drain the battery has on it. Keep turning on stuff the test light will get brighter.

Do this test to each positive terminal coming off the positive+ side of the battery.

 

This is one of the best and most simple test ever for checking a battery for drains. I picked this up working with GM engineers in school and have been using it for 30 years now.

[muffinman]

John do a voltage draw check and then remove the battery sensor and recheck the draw Dokons battery was going dead over night and I found that the sensor was the problem.

Just a thought.

Jeff

[frankd]

Also, unplug the voltage regulator (I know, it's new, but....) and measure the load resistance. One of the diodes could have become very leaky and cause this very problem. BTW, the test light method to determine current draw is excellent. I also recommend it all the time.