Tried starting up the bike last night, took longer than normal to start while turning over, and two attempts...then started. I figured it had sit for a couple weeks and I forgot to attach my tender...no big deal.

So I took off to recharge the system the easy way. Had to stop for a fill up a little while later...sure enough took several tries to get her going, so I figure I have an issue at this point...straight home I go.

Get home....

- Battery reads 11.4 volts, a little low.
- Start her up and get 13.6 volts, still low.

Start checking things in the two stickies....using a high end Fluke meter.

- Disconnect stator from regulator and check all 3 leads to ground, open/infinite (stator good)
- Check resistance from stator pin to stator pin (all 3), 2-3 ohms (stator still good)
- Start bike, and check AC output of stator at idle (all 3) 28V AC (stator still good)
- Check 3 pins on regulator to ground for DC, all three measure 0. (regulator good)

Couple things I am not sure of:

- How do I check the output side of the regulator?
- When everything is connected, and the bike is running, if I rev up the engine the most I can read at the battery is about 13.6. Is this because my battery is still low? or does it mean the output side of the regulator is kaput? (hence the first question).

I currently have my Battery Tendor JR. on the battery to fully charge to test that again.

Once fully charged, I plan to run up to Autozone to have the battery load tested as well.

Anything else I should be looking at? I think my two possible issues per my testing could be:

- Battery (should know after charge and load testing)
- Regulator (output side)

Thanks for reading, and I appreciate any criticism or feedback.

Brian

 

See comments in the text above.

 

Ok, regulator output is low, but not that much. I see 13-15 being a normal range.

 

Just an FYI on what I ended up finding.

Battery was bad - I dropped it off at the dealer to be tested/charged. They let it set overnight, called me the next morning and let me know that it was toast. Luckily they replaced it for me since it was supposedly new when I bought my bike in May.

After replacing the battery, and cleaning all the connections in the charging circuit, I am getting 14.1v at the battery with the bike idleing, and up from there a bit if I rev it up.

All my tests were good, except that with the old battery in place, I was only getting 13.6v at idle. Still not sure why that is, as it was suggested the battery level shouldn't affect the regulator output when running....I guess it could be all the connections I cleaned, and added dielectric grease to...

Anyway the stickies in this section were invaluable, easy to follow, and allowed me to make a fairly quick diagnosis.

Thanks for the feedback, and especially the stickies.

 

Guess it already been said but some facts. Also, most important. Hold the starter switch in till it's running. False starts and letting up on switch just makes it harder to starts and causes bangs from kick back that 90% of harley people say compensator problems, starter sprag clutch problems , so on and so forth.. ect.....

After a good 24 hour low amp controlled charge and the battery has set about 24 hours voltage should be about 12.8 volts.
12.8 = full charged
12.6 = 75%
12.3 = 50%
12.0 =25%
With a DC volt meter (that has a feature to lock high and low reading is best) hooked across the battery terminals and reading 12.8 or so, crank motor and while its cranking it should not drop below about 9.6 volts and as soon as it starts and throttled up to 2000 rpm or so should read around 14.8 volts. The 2000 rpm is the bench mark standard. The crank check shows a rough check of the reserve amperage capacity of the battery while cranking with a 150-200 amp load on it. The 14.8 shows a good alternator and if you leave it on a while as the regulatory will drop the voltage a little showing itself working. However, with the lights and stuff always on it will never drop back much.
When a battery wears out a good charge will show fairly good voltage, but the battery can still have very low amperage capacity which will show in the crude crank test above, but it really should be checked after a good charge by removing it from bike and getting a free check at a place like AutoZone that has a fancy load meter check that gives you a print out of the battery health. Battery MUST BE CHARGED to check it. Be sure they set their meter to correct cold cranking amperage stated on the battery. Never charge the AGM absorbed glass mat battery with a regular car battery charger unless it is a newer one that says safe with this type of battery. Also by taking battery out you now know you have good connections. Vibration tends to loosen the connections or a little corrosion will prevent charging or cause starting problems. Using the maintenance charger can get more years from a battery but be careful here. You do not want the last start 5 miles from home. If it still grunts when you first hit starter or kicks back, replace it. After a few years, charge and pull battery and have it checked for cold cranking amperage ever spring. Even then, if it grunts most ever start, I would replace it. If they have one, Wal-Mart's AGM absorbed glass mat battery is just as good as any one's for half the money. Do not jump, push start or run bike with a half dead battery except in an emergency. It will kill alternator stator or the voltage regulator or both. Probably a $500 repair.