High test gas

[RvP]

Dave,
It seems your second question regarding the polarization of your electrical system got lost in the discussion. All generators need to be polarized regardless if they are 2 brush or 3 brush. Polarization of the generator puts a residual magnetism on the pole shoes that the field windings are wrapped around. This residual magnetism allows the generator to self excite and produce voltage of the correct polarity. If the generator is not used for a long period of time, subjected to extreme heat or extreme mechanical shock the pole shoes may lose their magnetism and the generator will appear to be dead. That’s the technical reason.
Since your description is that of a 3 brush generator let’s focus on that. The 3 brush generator has two separate fields, one is the regulating field connected to the 3rd brush and the other is the shunt field that gets 6V applied when the headlight is turned on.
To polarize a 3 brush Harley generator the easy way you should only need start the engine and turn on the headlight (if wired correctly). This will energize the shunt field and start the armature producing voltage. The armature voltage will then polarize the regulating field (the 3rd brush field) automatically. The gen light in the dash should turn off. To verify the generator is polarized turn the headlight off and the generator light should stay off.
If the generator light in the dash is still on in either case (headlight on or off) bring the RPM up. If the gen light does not go off suspect something else is wrong other than polarizing the generator and turn the engine off.
The harder way is to momentarily connect the armature post (relay) on the generator to the battery with the engine off. I prefer to do this with a wire right from the + of the battery to the armature post to bypass the wiring, switches, fuses and circuit breakers (if installed for protection). Connect a wire to the + of the battery and swipe it across the armature post on the generator to make a spark.
If you do not have any fuses or circuit breakers and properly wired you can do this by turning on the headlight and momentarily touching the two terminals on the generator together to make a spark. This last method will momentarily pull 2 amps through the wiring harness and ignition switch which should not harm anything if you have the proper wire sizes, lugs and switches. If you do not get a spark with either method then suspect something is wrong.
If all of the above fails then something else is wrong and needs deeper diagnosis. Some things I have seen:
- Fuse or circuit breaker blown or open.
- Wires reversed on the generator terminals.
- Wires in the wrong places on the cutout relay.
- Cutout relay contacts not clean.
- Cutout relay winding’s open or shorted.
- Reproduction cutout relays internally wound incorrectly. (Note: The cutout is not a simple relay, it has two windings that sometimes aid each other or oppose each other. If these are wound incorrectly the contacts will oscillate and burn.)
- Broken and missing brushes in the generator.
- Shunt field connected backwards inside the generator. (Note: When the lights are on energizing the shunt field and wired backwards it is of opposite polarity than the regulating field. The stronger field will win and can reverse the polarity of the generator.)
- Open field or armature windings.
- Shorted field or armature windings.
- Shunt field wire on generator incorrectly wired on the ignition switch or junction block. (Note: I have seen it placed correctly on the ignition switch but in the wrong post on the junction block on the fork.)
- Pinched and broken wire between the frame and tank.
- Generator gear fell off or not pinned to the generator shaft.

I am sure there are more and the above is my list of things I have experienced.

[RvP]

I need to make an important correction to the above!!!!

When I stated the generator can be polarized by shorting the two terminals together at the generator when the headlight is on I did not take into account that the armature looks like a dead short! The statement “will momentarily pull 2 amps through the wiring harness and ignition switch” is entirely wrong! Doing this will put a dead short across the wiring harness and can damage switch contacts and smoke wires. Do not do this unless you want to take the risk of causing damage.

My apologies.

[Dave Rumbel]

Thanks RvP
I'm not having any problems with it. Its just that I keep reading that if you disconnect your battery, you have to repolorize it. But in all my books none address the relay, only the three post regulator located above the oil pump. I have an inline spade fuse just off the positive post, when the bike sits I have a battery tender on and I take the fuse out just for safety, (all those wire connections right on top of a full gas tank scares me a little). So you say if I start it up and turn on the headlight, that should take care of it? I never had a problem with the gen light not going out, at low idle sometimes it flickers.
I'm considering installing one of those regulators that replaces the relay, Red Fred had a good wright up in the spring issue, but it sounds like its not available yet.I have a gell battery in her and I read that the relay isn't steady enough for them and burns them up. Any thoughts on that?
Thanks alot for the info,
Dave

[RvP]

Dave,
I think having a fuse on the battery’s hot lead is an excellent idea and one that I also employ. Makes it easy to remove the battery voltage if an electrical fire starts. It also prevents doing damage if you accidently short something while working on the motorcycle (which I have done many times).

It is not necessary to re-polarize the generator every time you disconnect the battery but good practice if the generator has not been used in a long period of time (as in weeks) or if you are replacing a faulty component that caused the generator to not function properly (i.e. fields, armature, brushes, regulator, wiring, etc.). Failure of any of those components can cause the residual magnetism in the pole shoes to diminish and in some cases can cause the magnetic polarity to change.

For what you are doing by removing the fuse to put on the battery tender you know the generator was working properly prior to putting on the tender and therefore polarization would not be necessary unless you had not run the motor for a long period of time. Regardless of that, turning on the headlight will do the polarization which in this case is really refreshing the magnetism on the pole shoes.

The gen light will flicker at idle if the idle speed is so low the generator’s output is below the voltage the cutout closes at. If the gen light goes out with a small increase in RPM I would not be concerned. If the RPM has to be really high then I would suspect the 3rd brush is out of adjustment or the cutout needs to be adjusted and cleaned (a solid state cutout will eliminate all those problems)

With regards to the voltage regulator that replaces the cutout you will need to convert the 3 brush generator to a 2 brush generator to use one. The 3 brush generator can be rewired for this and requires removing the generator and rewiring the regulating and shunt fields inside the generator. There is a “shop dope” for the 32E that shows the before and after rewiring. The only caution is on old generators the field wires may be brittle and the insulation may fall off exposing the wires when moved. These would need to be dressed with heatshrink or tightly wrapped with electrical tape.

I prefer a regulated 2 brush generator over a 3 brush, especially if you have accessory lights or drive at high speeds with the headlight on. It is also better for battery health to have a regulated charging system. I have 2 bullet lights on the rear of my WL and I drive in the daytime with the high beam on. I found the battery was not always up to peak and I added an external shunt regulator to keep the 32E 3 brush in check. This worked but was only a short term fix and stressed the generator. I finally went to a 2 brush regulated setup but not the conventional way. My conversion did not require rewiring the generator but only removing the 3rd brush, adding 1 wire and mounting the voltage regulator under the left footboard. I still retain the stock 3 brush wiring and cutout. So far I have only done this on my WL with a 32E and it works great. I am waiting for a friend to do the same conversion on his panhead to see if the results are the same. The cool part is if the regulator should fail far away from home you only need to put the 3rd brush back in and it’s back to a stock 3 brush setup. I sent this to Red Fred for his opinion months ago and I am waiting for his feedback before I suggest this and give bad advice on a sample of only one.

My opinion of using a sealed battery with a 3 brush system is not favorable. A 3 brush generator continues to force feed current into the battery even after the battery is charged up. Any current not needed inside the battery turns into heat causing the battery to get hot. This is why the traditional lead acid batteries boil over. A sealed battery has no specific venting to displace the expanding gasses and even if they do vent, electrolyte is lost diminishing the battery’s capacity. If the sealed battery is not robust enough to take continual current of 2 amps (or more) at voltages above 7.25V and lots of heat then it will fail. Unfortunately I don’t know enough about the sealed battery types out there and their specifications to know if there is one that meets the criteria. I am sure people have successfully used sealed batteries with a 3 brush system and their opinion on what is a good sealed battery to use is better than my opinion.

One more thing to consider with a panhead, the battery is surrounded inside a hot environment due to the oil tank. This already adds extra heat to the battery. I know that when you convert to 12V with Cycle Electric components they recommend a different voltage regulator for panheads than 45s. The reason is the 12V battery is small and being inside the oil tank on the panhead adds extra heat on top of the heat imposed by the generator. The Cycle Electric panhead voltage regulator keeps the electrical system at a lower voltage (13.8) further reducing the heat in the battery. On a 45 where the battery is not surrounded by a hot oil tank the recommended Cycle Electric voltage regulator has a slightly higher operating voltage (14.5). This should also be taken into consideration when selecting a sealed battery that the ambient environment the battery is exposed to is going to add heat.