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sjeccles
20th May 2005, 19:40
I just put a new wiring harness on my 77 XLH. The manual says to polarize the Generator whenever the wiring is unhooked. The instruction tells how to do it at the regulator but mine has been converted to an electronic regulator so I can't do it like the book shows. Do I still need to polarize it since itís an electronic regulator?
Thanks

dabronco
20th May 2005, 19:49
Yes you do. You are polarizing the generator, not the regulator. Look in your manual, they show more than one method of polarization. Call an auto electric repair and they can give you other proceedures for doing it if your manual isn't like mine. I am at work and don't have access to my manual.

sjeccles
20th May 2005, 20:20
thanks you for the quick answer

Y2K
20th May 2005, 20:53
You can flash it from the battery directly to the generator. :smoke

sjeccles
20th May 2005, 23:51
thats the positve side to the A post on the generator? Right?

Y2K
21st May 2005, 03:56
thats the positve side to the A post on the generator? Right?


Yes...here's what it says in the H/D service manual under "Polarizing Generator".

"Generator on motorcycle and connected to regulator:
Connect one end of a jumper wire to the generator armature terminal.
Momentarily touch the other end of the jumper wire to the positive terminal of the battery.This restores the magnetism.Remove jumper"

So yes , battery + to A (A = armature) just touch it for a second and you may or may not see a spark.No spark doesn't mean it didn't work,it may already have the right polarity.Good luck! :D
Y2K

IronMick
21st May 2005, 04:14
I keep a 4 ft piece of insulated 16 gauge wire with an alligator clip on one end, specifically for this task. Clip it on the gen A terminal, touch the other end to the battery +ve, roll it up and hang it on the wall, ready for the next time.

sjeccles
21st May 2005, 05:28
Thanks Guys

golden236
20th July 2008, 23:33
I have a 74 Ironhead and have seen in my manual that you should jump the GEN and the BAT directly at the regulator for 59-77 models, and for 78-84 models jump BATT to A terminal. Is it not going to work if I jump from the battery to the generator on my 74? I ask because my regulator is a mother to get to. Thanks guys

72 Ironhead XLH
20th July 2008, 23:36
will work that way too,

IronMick
20th July 2008, 23:46
Yes, and welcome to the forum!

shabazz18
15th January 2010, 08:13
Will not polarizing hurt anything? Besides draining the battery and leaving you stranded of course.

GA_Ironhead
15th January 2010, 14:02
I believe I've read that when the generator is not properly polarized, the contacts on a mechanical regulator will prematurely burn and wear, due to excessive arcing.

IronMick
15th January 2010, 14:54
From ACCEL:
Incorrect polarity may result in relay, battery or generator damage.

My own experience is that it may do not damage during a short ride, like 10 or 15 minutes. Other than that i do not know.

To really answer this question one would have to understand exactly what is happening electrically, which i do not.

SpringerSam
15th January 2010, 15:23
Mick,

A generator can deliver current for either a positive or a negative ground system?

A generator produces current by passing conductors (the armature windings) through a magnetic field. The magnetic field is produced by electromagnets that surround the armature. Basically, the field portion of your generator consists of copper windings around iron core, often referred to as the pole shoes.

The voltage and current delivered by your generator is determined by the strength of the magnetic field and the speed at which the generator is running. But, the polarity of the current is determined by the polarity of the pole shoes, or the direction of the magnetic flux or field, which is determined by the direction of current through the field windings.

When you start your engine, the generator will start delivering current. Since the generator is still isolated from the electrical system by the voltage regulator it will start producing current based on the polarity of the pole shoes. As soon as it begins producing current, some of that current will be directed to the field windings to strengthen the magnetic flux.

If the generator polarity is reversed, the generator will build up voltage and close the cutout relay points. This put the generator in series with the battery, and their voltages are added together. This high voltage across the points (about twice the battery voltage) can cause high current and enough heat to weld the points together.

This damage does not happen immediately. The instant the points close, the voltage is about the same on both sides of the relay coil, so very little current flows, and spring tension reopens the points. But, generator voltage will again close the points, and the cycle will repeat at a rapid rate. Heat and arcing will finally weld the points together.

When the points weld, the battery and generator are connected at all times. The low resistance of the generator allows the battery to continue to discharge through the generator. The high current can create enough heat to burn the armature.

How do you control the polarity of the pole shoes? The polarity is determined by the direction of the last current through the field windings. Since even a very small current can polarize the shoes, never assume the generator is properly polarized. You must polarize the generator every time it is disconnected or serviced.

To polarize the generator, simply make a short jumper wire to short between the battery (b or bat) and generator (g or gen) lugs on the cutout relay or voltage regulator. Only a split-second or a spark is required, so simply tap your jumper wire onto the lugs and pull them right back off.

Reference: John Deere Fundamentals of Service (FOS): Electrical Systems, Fifth Edition. 1984. Chapter 4, Charging Systems. John Deere Service Training, Dept F, John Deere Road, Moline, IL 61265

Fe Head
15th January 2010, 16:07
From ACCEL:
Incorrect polarity may result in relay, battery or generator damage.

My own experience is that it may do not damage during a short ride, like 10 or 15 minutes. Other than that i do not know.

To really answer this question one would have to understand exactly what is happening electrically, which i do not.

In addition to what others have said above it is important to understand what is going on inside the typical generator.

The soft iron shoes on either side of the armature are very very poor at retaining residual magnetism and will become "apolar" or magnetically neutral very quickly leaving virtually no magnetic field lines crossing between the internal shoes of the generator.

When this situation exists the startup initial rotations of the armature can easily set up the first flow of the electrons opposite to what is needed relative to the battery's polarity.

This is not a good thing to continue without grave cosequences

As all typical DC motorcycle generators are of the parallel shunt self excitator design once the reversed flow is established it will porduce and maintain the reversed North, South poles.

Moreover, it will never correct its self without active intervention.

If our Sportster's generators were of the series external excitator type this step would never be needed - however they are not therfore polarizing correctly guarantees a positive outcome everytime.

Cheers;

shabazz18
15th January 2010, 19:31
I wonder if it would fry a solid state regulator as well. My main concern is with the generator, as I just got this thing back and its not charging.

BuckIRyder
15th January 2010, 22:31
Same as you Mick, I keep a jumper on the wall in the garage. Doesn't matter which place you jump from be it the battery plus terminal or the B+ terminal on the regulator (mechanical).

drphil81
12th February 2010, 19:45
If testing for polarity with a meter, at what point do you determine that it is correctly polarized. I need to eliminate possible faulty wiring, generator, and/or regulator. Due to not properly polarizing the generator, I was left stranded and had to push the bike about a mile to a friends house. Now that I have polarized and recharged the battery I am wondering what rate the meter should read at.

ryder rick
12th February 2010, 20:17
What you are doing when you "Polarize" a generator is to set up the residual magnetism in the field poles.

Since the generator is self exciting (self powered) it relies on the residual magnetism in the poles to get itself started.

It depends on residual magnetism to make voltage to provide power to the field windings at startup.

This allows the bike to be push started with a dead battery, and eliminates the need to provide external power to get the generator started.

When a generator sits for a LONG period of time without running it may loose that residual magnetism. Or when a generator is rebuilt the pole pieces may get swapped or be new and thus may not have residual magnetism or the polarity of the residual might not be correct.

A working Generator light with a fully charged battery will usually get a generator running that has been previously run and not disassembled. The back feed voltage through the gen light from a full battery is not as strong as a "polarization" but has the same effect.

NOTE: When polarizing do not strike the F terminal by accident, you will burn the field control relay contact in the regulator and ruin it. And probably smoke an electronic regulator. Just one touch is all it takes and instant junk...

Billyjd
28th July 2014, 14:35
Ok, my generator doesn't have the A & F markings - it has 7 & 8. I'm installing a new wiring harness as the previous owner was an idiot and hacked the old harness to pieces & wasn't even using a voltage regulator. Has anyone seen a generator with the 7 & 8 markings? If so, which is A & which is F?

Fe Long
28th July 2014, 15:17
Typically the "A" terminal is closest to the front wheel while the "F" terminal is nearer the engine.

To be absolutely sure undo the two (2) bolts holding the end plate on and slide it back a bit - the "A" terminal lead will terminate on the graphite brush while the "F" will lead back to the field windings wrapped around the iron magnetic shoes.

If your using an Ohm Meter the "F" to ground will be high - ~ 18,000 ohms while the "A" to ground wil be less than 1 ohm.

All the best;

83XLX
28th July 2014, 15:58
I'll add that the generator will retain its polarity for short periods of time, like when the battery cables are disconnected to install a new battery. No need to polarize it in these circumstances, but there's no harm in doing it, either (if its done correctly).

Doc308
28th July 2014, 16:34
There is a great step-by step video on You Tube titled "Harley Generator Check".

hcrashster
30th July 2014, 02:17
I'll add that the generator will retain its polarity for short periods of time, like when the battery cables are disconnected to install a new battery. No need to polarize it in these circumstances, but there's no harm in doing it, either (if its done correctly).

Quality units will retain polarity for months if not years.

With that said;
Imports use questionable, pole parent material. Understandable problems with alloying, as iron is only as good as what is melted to make it. :doh

Fridge
30th July 2014, 02:39
Ok, my generator doesn't have the A & F markings - it has 7 & 8. I'm installing a new wiring harness as the previous owner was an idiot and hacked the old harness to pieces & wasn't even using a voltage regulator. Has anyone seen a generator with the 7 & 8 markings? If so, which is A & which is F?


If you have the late 1984 Ironhead, you have an alternator,not a generator.
Whole different ball game, with similar rules,but different.

So I guess you have the early 1984.

IronMick
30th July 2014, 03:05
Ok, my generator doesn't have the A & F markings - it has 7 & 8 ...

Never heard of this before now. Please post pic of the gen and of these markings.

Fridge
30th July 2014, 03:29
I wonder if it's a volkswagen generator?
Nah, I think they had Df and D+ denoted on the housing for terminal connects.

mcgoral
30th July 2014, 09:01
I wonder if it would fry a solid state regulator as well. My main concern is with the generator, as I just got this thing back and its not charging.
Reverse polarity will destroy the voltage regulator - cited from Custom Chrome 28-092 solid state voltage regulator (http://www.jpcycles.com/instructions/pdf/380-497.pdf) manual.

83XLX
30th July 2014, 14:47
Quality units will retain polarity for months if not years....
True, but I wanted to "cover the bases" for those that are of lesser quality. Bottom line is, a generator doesn't need to be polarized every time a wire is unhooked and reattached.

hcrashster
30th July 2014, 17:45
True, but I wanted to "cover the bases" for those that are of lesser quality. Bottom line is, a generator doesn't need to be polarized every time a wire is unhooked and reattached.

Understandable.

I have a box full of import generators in varying states of disassembly. The only thing they have in common is that they are not Cycle Electric or OEM units. No two failed exactly the same way, and none are worth repairing.

Money, Time and Frustration are all these POS imports are worth.

brucstoudt
31st July 2014, 00:58
Bottom line is, a generator doesn't need to be polarized every time a wire is unhooked and reattached.

that's interesting,because my 900 service manual,say's to do so. i'm not arguing with you,i do it because it's cheap insurance.

Fridge
31st July 2014, 01:40
that's interesting,because my 900 service manual,say's to do so. i'm not arguing with you,i do it because it's cheap insurance.

It's also interesting that my 1000cc FSM says:

It is advisable to "flash" the field coils whenever wires have been removed from generator or regulator; or after generator or battery has been removed and is re-installed.

I like cheap insurance, so I'm with brucstoudt, I do it regardless.

IronMick
31st July 2014, 03:02
I polarize mine any time i have had it off the bike and onto the bench for service.

trappnman
31st July 2014, 14:12
I do it as cheap and easy enough to do-

have always heard "sometimes you hear a click when polarizing, sometimes not" and I always took that to mean if you did hear a click, you actually were doing a needed service, if no click it didn't need polarizing

ryder rick
1st August 2014, 02:01
No need to polarize unless you have removed the field coils.

Don't make me repost my rant! :^)

trappnman
1st August 2014, 14:58
No need to polarize unless you have removed the field coils.


I admit, I know just enough about generators to be dangerous, and that's mostly info on how to keep em on the road.

I've always been told (and read) to polarize- and always do.

so RR- explain to me in more detail. When you say "unless removing coils" do you mean removing them from the body? or mean "removing" them from the armature via removing armature?

I've had them do nothing (when polarizing) I've had them click, I've had them clunk- does any of that mean I'm actually polarizing it?

I also had one where when I put it on, I had reverse polarity (polarizing did nothing to reverse it, I took it in and )- that I had to take in because it baffled me.

so when should one be polarized? anytime its disconnected? I should note, I never do it when I take batteries out/in.

anytime its taken apart? only when coils are removed from body?

what's the definitive story?

trappnman
1st August 2014, 15:58
ok RR, I went back and read your post #20

to my best recollection, I don't repolarize every spring when /I get bikes going again...and that would be 5 sometimes 6 months (God, it sounds awful when I see it in print but that's MN) so logic tells me polarization isn't needed as often as per manual.

why then would you suppose that instruction?

so let me ask you this- if you took a generator off, took out apart and cleaned it- would it need repolarization?

Fe Long
3rd August 2014, 17:08
My understanding of the "polarization" process is not so much about the polarity of the magnetic field within the generator as it is about having the optimum magnetic flux density present when the armature starts to rotate.

The shoes or poles inside the typical Sportster styled generator are composed of an annealed or "soft" iron which by nature has a very low value for coercivity.

The low coercivity of theses shoes mean they will loose their magnetic dipole moments fairly easily leaving a weakened magnetic field often with too low of a flux density for the electrical charges in the armature to start generating a reasonable voltage on startup.

Snapping the "A" terminal a few times at full battery positive voltage while the "F" terminal is well grounded will re-magnetize the shoes by way of the field coils AND restore the flux field's density between the shoes as a by-product.

The polarity does not change but it is, however, reinforced.

The audible clunk or clink heard sometimes is simply dependent on the angle the active conducting loop of the armatures is at with respect to the magnetic flux lines when the polarization event occurs.

1. If parallel to the flux lines the will be no sound or movement.

2. If above or below a little bit then a muted clink

3. If above or below more so and there is enough free play in the drive gears a solid clunk can be expected.

All the best;

trappnman
3rd August 2014, 19:19
interesting to know

thanks!

ryder rick
3rd August 2014, 20:51
Any residual magnetism in the field poles will cause power to be generated, that power is fed into the fields, causing even more power to be generated. When that power reaches the set level in the regulator the A term is connected to the battery so the battery receives charging power. When the charging voltage exceeds the set point in the regulator the regulator lifts the ground on the F terminal and voltage output drops. when the voltage drops below the set point in the regulator the regulator grounds the F terminal to raise the voltage. This cycle of events repeats at a very fast rate and is called regulation. :^)

The clunk you hear when polarizing is the armature being pulled into the center of the field poles. Differing end play and mfg tolerances makes this sound or lack of it different for every generator.