Regulator Test Charging Problem

[hdfx78]

Is there any test that can be made with a multi meter and the regulator off the bike? This is the 1978 electronic version. I have tested the generator on the bench by running positive to  Arm and negative to Field and case and it spins free like an electric motor would. So that seems to put my charging issue back to the regulator. Gen light stays on too. Looked but did not seem to have a short in the light circuit. Does anyone know what rating diode should be in line to the light? If you can suggest another test with everything in the bike that does not require a lot of equipment I am interested as well. The only thing holding me up is the charging problem. Then just a few tweaks I may ask for help with later but the juice is the priority.  Thanks, Mark HDFX78

[saltcaveminer]

most testing requires the engine running at 2000rpm.the manual does show a test using an ohmmeter with the regulator disconnected.disconnect the rubber plug and connect an ohmmeter between battery and generator wires(orange and tan)reverse the leads and read again.readings should show continuity  and then open when reversed.Salty

[hdfx78]

Thanks Salty, that test checked out so now back to the battery. New about a month ago. 75 miles on bike while working on it. Used Battery Tender when it wasn't running. Over 24 hrs on charger now and won't take a charge. Checked cells and only two will float 1 ball on the tester. Maybe battery bad and not the charging system? Large battery for electric start. Any suggestions welcome. I am checking every wire and all looks well.

[Ironhead RON]

Did you ever polarize the regulator to the generator when you installed the new battery ? Just because the generator spins does not prove the generator windings are good. Check the battery charger output when disconnected from the battery circuit and then when hooked up and in the circuit. Charger output should be much higher, about 15 volts no load, (when not hooked up.) And then drop off to about 13.8 volts when charging the battery. The finish charge on the battery should be at least 12.6 volts. I use a voltmeter to check individual battery cells. Start at the neg post with the neg lead and then put the pos lead into the acid on the nearest cell. Should be 2.1 volts. Each cell in turn, should be at least 2.1 volts more per cell. Or then place the neg lead in to the cell nearest the neg post and the pos. lead in to the next cell. And then repeat from cell to cell until you get to the pos. post. At least 2.1 volts per cell should show.  Does not hurt the battery but make sure you neutralize the leads after. Pure acid for the new battery cells and afterwards only add distilled H20 as a top off fill to each cell. Sounds like you got a bad battery or created it through a non charge situation. Make sure the polarize test flashes strongly not weakly. Do it a couple of times in quick succession to make sure.

[hdfx78]

Thanks for the tip on checking the battery. I will use it and yes I definitely have an issue with charging still.  I did make sure and polarize the gen more than once too. Battery said see ya later at about 50 miles from home. Did use the kicker and started first kick. That was rewarding but only got about 3 more miles  before she said good night. That was yesterdays adventure. Got her home now and gotta get it right. I did find continuity between ground and the orange wire that feeds the GEN light, headlight and front brake switch. When the key is on this reads 12V positive feed. With key off shows ground but flip kill switch or open points and no longer grounded. Maybe the problem. Looks like I am right by wire diagram. Does this shed any light to anyone out there? I will update.Thanks again for all replies. Mark HDFX78

[Ironhead RON]

Generator is a driven unit by the gear connection, not like a starter which is a a driving unit. If no output from the generator then you run on the battery until battery dies from lack of volts replacement. Reason for the regulator is what it suggests. Regulate the battery input so battery does not over or under charge. Salty has a good point too. The faster the RPM of the motor the greater the charge capability. Too slow, like at idle, may not charge at all. Could be wiring or bad generator windings or a bad regulator. Any one of the three will cause problems and no charge. Any two of the three causes confusion and no charge. Try a fresh battery, possibly a gel type, which usually come near fully charged. And does away with the acid drip tube. I had the ohms, (Resistance readings.), for a typically good and bad regulator somewhere and will look for it. It would pay to get a spare regulator now as the price goes up and up like crazy. Don't know your persistence or cash flow ability. But hang in there. Electrical problems can be a bee-yitch on these older Harleys.

[hdfx78]

Yes .....electrical problems. I'm all dressed up with nowhere to go. Did this 78XLCH with my son from the basket and this has been the only snag but dam. I rode this thing and feel in love with it. Need to watch out on the break in and take it slow cause it really has potential and wants to go. Thanks for the support. Been some long, lonely nights in the garage lately with nothing to show for it.

[saltcaveminer]

are you using all the factory connectors?if so check them all. check that tee connection (tan)near the regulator rubber plug.have any splices been made?are you going directly to the regulator (red from main cb to orange rubber plug?) is the regulator properly  grounded?(blk wire)are all other devices working properly? ex headlight,brake lights ,horn etc. just some things to consider, dont quit it will work out! Salty

[hdfx78]

Success!!!! After all that it turned out to be the regulator. Reg checked out by the  continuity tests but turned out to only have about half the Resistance of the new one. I guess that was it. Put it all back together, Polarized the gen one time and got charging volts and light goes out from about 1000 rpm on up. What a bugger! Hopefully this may contribute to someone Else's situation in the future.
On to dialing in timing and carb. I may be back, this is a great board. I have showed this to my son so that he knows where to go in the future as well.
Thanks Again, Mark HDFX