12V Generator testing

Electrical issues
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hd_vince

12V Generator testing

#1

Post by hd_vince » Tue Aug 21, 2007 9:36 pm

what is the easiest way to check a 12V generator (model 65A) outside the bike.
I can run the generator as a motor by jumpering the A and F terminals and put 12V to it (and ground to the housing). Runs regular.
Looks OK so far.
When I spin the generator (by using a beltdrive on a drilling machine) it only outputs 3-4 Volts.
Checked field coils, no short circuit, 2 amps in series on 12V supply which is OK according to HD manuals.
To my opinion armature looks OK, mica cut etc. No signs of damage or burned. I don't have a growler to check.
Any ideas??



john HD
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#2

Post by john HD » Wed Aug 22, 2007 1:37 am

ground the field and retry your belt drive test.

john

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#3

Post by wla421 » Wed Aug 22, 2007 5:16 am

Try this site..

www.cycleelectricinc.com

Drop down to Tech...

George in Germany

hd_vince

generator testing

#4

Post by hd_vince » Wed Aug 22, 2007 7:45 pm

john HD wrote:ground the field and retry your belt drive test.

john
Tried this but no luck.
I got 3-4 Volt on the A terminal and 0 on the F terminal (before grounding of course!) Jumpering A-F results also in 3-4 Volt against the housing.

Does anybody have a drawing/sketch of the internal wiring from terminals to field coil and armature back to terminals to be 100% I didn't make any mistakes here.

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#5

Post by panhead » Wed Aug 22, 2007 8:59 pm


Guest

#6

Post by Guest » Thu Aug 23, 2007 4:30 pm

Thanks Panhead,

the drawing is for a 3 brush, I had this drawing already for my liberator.
I can't seem to find one for a 2 brush.
Would be OK just to describe:
- from F-terminal to 1st field coil
- other side to 2nd field coil
- from other side to brush
- through armature
- other side to A-terminal

So basically field coils are in series with armature between A and F terminal, correct?

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#7

Post by panhead » Thu Aug 23, 2007 9:18 pm

Here's a two brush:

Image

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#8

Post by Cotten » Fri Aug 24, 2007 1:18 am

Whoa,... 65A generators are very different.

And testing requires measurement of amperage.

If you are not using a fully charged battery to test with, you will not get a proper output. Three or four volts sounds like no battery.

Time to buy a manual ('58 to '69), its all in there!

...Cotten

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#9

Post by FlatHeadSix » Fri Aug 24, 2007 5:27 am

Like Cotten said: "sounds like NO battery"

Remember, its a generator, not a dynamo or magneto, so it will take voltage to make voltage. You must put 12 volts on the field windings or they will not create the required magnetic field which induces the current in the armature. Without external power all you have is the residual magnatism in the pole shoes (the iron plates that the field windings are wrapped around), so all you'll get is the 3 or 4 volts that you are reading.

If you are bench testing it by spinning it with a drill motor or whatever, you have to have all the components which are normally in the circuit: A good battery and a regulator. Connect it just like the diagram.

If it will "motor" when you connect a 12 volt power supply then it is probably OK.

good luck!

mike

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#10

Post by fourthgear » Fri Aug 24, 2007 1:41 pm

If you look at the manual , you will need to have some special equipment to do a good test on the generating circuit , good amp meter or clamp type amp probe , rheostat , a load ( could use the head light )and as said above the other components in good working spec's.. There are still shops ( automotive ) that test generators , (you will have to call around),just to see if the Gen. is up to spec's and you can go from there with the other components and do not forget about the wiring, it is sometimes over looked in charging problems .The manual has things you can check ,like continuity of field coils, armature,commutator bars and brushes that can be done with a simple multimeter. Worn bearings can cause problems if worn badly.

Guest

#11

Post by Guest » Mon Aug 27, 2007 12:11 pm

I got the '65 Pan HD manual but can't figure out the INTERNAL wiring

The link found on this great forum showing the 12V chevy generator internal wiring makes more sence to me but is this as a 65A type HD generator??

I agree with all of you saying you need to test it as a whole system since it obviously needs power to generate electricity.
I arranged to have another generator and same result... so afterall the problem will be somewhere else. Battery (level) is OK and bike will electrical start. Will check wiring and regulator tonight.
However, regulator is electronic so I don't know what can be tested to rule out it's (mal) function.
any suggestions here?

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#12

Post by john HD » Mon Aug 27, 2007 12:59 pm

if the genny will run as a motor and you have enough battery to start the bike that pretty much leaves the regulator and the wiring as the suspect components.

put it all back together and install a temporary ammeter in the positive (small) wire to the battery. then run the motor around 2000 rpm, ground the field terminal and see if it charges. if it does, replace your regulator.

john

DMac

12v gen test

#13

Post by DMac » Tue Sep 11, 2007 4:09 pm

Hey, how 'bout this one?
Have been having problems, pretty much knew it was the regulator-(solid state). Decided to try grounding the field just for the heck of it, I just flashed the field to ground and the generator light went off and after several days of riding it has stayed off when engine is running and seems to be charging just fine! Not sure what to think, is it "fixed"? and if so why?
Anyone out there have any ideas?
Doug.

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#14

Post by FlatHeadSix » Tue Sep 11, 2007 4:44 pm

Doug,

The solid state units, nothing mechanical and no moving parts, depend on "triggers" to toggle the circuits and a small amount of residual voltage to maintain the memory so it knows where it is, on or off.

Once in a while they forget where they are and everything gets reversed. when you "flash" it sometimes you get lucky and restore the original baseline. Exactly like rebooting a computer.

You probably fixed it, ride on!

mike

DMac

12v regulator test

#15

Post by DMac » Tue Sep 11, 2007 5:41 pm

Hi Mike,
Thanks for the reply. This one really had me scratching my head. It just seemed too good to be true that it might be OK. I'm going to continue to ride it as-is and watch it closely. If it craps-out again, I think I'll go to a small Bosch Sporty-type set-up.
Doug.

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