09/13/14, about noon. And to all veterans and their families, thanks for your service.

On my 2002 FXDWG Dyna Wide Glide, 88A, when I measure voltage across the positive and negative terminals of the battery with all accessories off, including the alarm system and lights, I get a small continuous discharge of voltage (hundredths of a volt). Just replaced the battery. I'm wondering if the regulator is not working properly, and allowing a back flow through the starting motor, resulting in the discharge. Perhaps the starting motor has broken down insulation and is shorting. I'm familiar with the normal tests to check for these irregularities, but other guidance would be appreciated. Johnny Joseph

 

I am not sure what you think you are measuring, but if you put a voltmeter across the terminals of the battery, you should read full battery voltage, typically 12.5+ volts. You might read something low like you indicate if you are using the ammeter function, but that does not tell you anything of use except the voltage drop across the meter...if it doesn't damage your meter first.

To measure battery drain, you do not measure volts, that will tell you nothing except that an electromotive force potential is present, not whether or not there is a current drain. To measure drain, you measure amps. You will have to take off either the positive or negative cable to measure amps. Taking off the negative cable is the most correct method to minimize the possibility of full current arching and damage.

After taking off the negative cable at the battery, you put the positive meter lead on the cable and the negative meter lead on the battery. If you are measuring from the positive battery terminal, the positive meter lead will be on the battery and the negative meter lead will be on the cable. You will set the ammeter to the highest setting and go down settings from there. The typical drain should be milliamps or zero amps, depending on whether or not you have a keep-alive circuit on your bike such as a security system or clock.

 

If you think you are getting more drain than what would be normal for "stay alive" circuits, try disconnecting various fuses to isolate it.

 

Thanks for the setback, Skinman. I just put the probes across the positive and negative terminals of the hooked up battery with everything off. There appeared to be slight drain. E.G., went from about 12.84 volts, and minute by minute, would go down to 12.83, then 12.82 etc. I just couldn't reconcile the load? Would the voltage tester itself comprise a draw in the 20 volt setting that would cause this. My trickle charge seems to be holding green when I attach it Regardless, thanks for the thoughts. Peace and thanks for your service (4th Infantry Division, 1967-68, II Corps, Artillery, University of S.E. Asia)

 

And, thanks for your service as well.

To determine if you are having parasitic current draw problem with your bike, you will have to measure the current drain like I explained. The voltage decline you are talking about is not a good test because it could be the battery, your meter, your meter leads, and a whole host of other things that don't indicate that you have a problem. Go back and do the static current draw check and if you are reading more than, say, 100 miliamps and don't have a stereo, clock, alarm system, or something like that, then you might have a problem. You can pull fuses and see what is drawing current like was mentioned.

 

With all off, the typical Harley with an alarm off or on is about 5 milliamperes (mA). Newer bikes are even a little less. Biggest draw is the disarmed or armed alarm and the ECM. Do not get the first 30 seconds of when you check it with the negative cable off and put your meter between it and battery post. It will draw 16-25 mA (which is that spark you see and hear when you attach) for 30 second before trimming down.

 

Don't over think this one. Remove the negative battery cable, install a 12v test light between the cable end and the negative post. If the test light lights, yes you have an excessive draw. If test light does not light. Clean cable, reinstall and ride.

 

Think a little bit.... never do positive first...

 

And think about this...would you rather have idiot lights or gauges? You will do the same work with a light or multimeter, and while the light will certainly tell you that you have a problem, the meter will tell you HOW MUCH of a problem, and decent multimeters are cheap.

 

My bad, brain fart. Post edited.