Electrical (charging) question...

[couchsachraga]

I think I'm on the right track here, but before I start replacing parts thought I'd check with the brain trust:)

Yes, yet again I'm working on my parents '65 cub. The problem for a while has been the battery discharging during use... which I've confirmed is because it's not charging enough.

Battery is good... with cub off 12.4v or so.
During crank over that drops to 10-11 and change as you'd expect.

At high idle (where I'd expect charging) it is 11.90 v or so. Turn the lights on and it actually INCREASES to 12.15 or so (+ or - depending on how many lights are on;) ).

Turn it back off, battery is at 12.20v (typically given power used for starting (cold up here and I don't have the knack for starting it I used to).

We did try re-polarizing the voltage regulator.

I'm guessing I may want to replace that unit.

Thoughts?

Thank you all in advance as always!

Oh, and that oil seal hasn't leaked a drop since it was turn around the other way:)

[John *.?-!.* cub owner]

Your description sounds as if the regulator needs adjusted a little. I have never done much work with a regulator, so cannot tell you how to do it, but here is a trouble shooting flow chart for regulator type charging systems. It does not contain regulator adjustments, but will help you pin point the problem. Note, when polarizing it is not the regulator that gets polarized, but the generator. It is done by jumping from the Bat (NOT FLD) term of the regulator to the Gen term of the regulator though, which provides a voltage to give a slight magnetic charge of the proper polarity to the laminations of the generator field.


image compliments of Farmall Bob.

[bythepond88]

As John suggested, start with the flow chart, to pinpoint where the problem is. If it is the regulator, check the air gaps on the coils in the regulator. I have brought two regulators back to life by doing that. I think the gap is .075, but check the manual to make sure.

[couchsachraga]

Thank you! I'll be following that this weekend, or perhaps before then depending on what snow we get.

I'll see if I can walk my mother through setting the gap over the phone... she's pretty handy with mechanical things.

[challenger]

I'll see if I can walk my mother through setting the gap over the phone... she's pretty handy with mechanical things.

Now that's a special mom, you must be proud. Perhaps you could talk her into joining this Club. We could benefit from her mechanical aptitude.

[Ironlegs]

Another feature to consider is adjusting the third generator brush...if your generator has one. Look under the removable band cover and see if there are three generator brushes. If so, one will be adjustable over about a 25 degree rotational angle. Changing its position will change the output of the generator. I adjust mine for more charge during winter use if I'm using the lights more. JG

[Bigdog]

If your system is charging normally you should get at least 14 volts at high idle. It may sound a little silly but have you checked the belt tension? If the belt gets just a little glazed it can slip under load. Try grounding the field and see what the generator output is with the regulator out of the circuit.

[Glen]

Hi,
The Cub parts book shows that the 12 volt generators had 2 brushes, and no removable band. Just wanted to post the info.
The 6 volt, 3rd brush could sometimes need adjusting.

[couchsachraga]

Well, they didn't make much headway, and I was up there today for a bit so I checked it out a little...

My first thought was to clean all the connections.

What I noticed was odd (and it may not be -it is the reason for this post) was that there was no wire to the "L" post ("F", "Bat", and "Gen" all appear connected correctly, and it is well grounded).

I did pull the cover off the voltage regulator - one side does move during operation, the other does not...(and yes, the side with the points that do not move is the one the "L" terminal wire connects too...).

It is a 12v system, so I"m assuming the 6v wiring schematic that came with the Cub may not be valid... but I"m not sure.

Oh, and it is a newer (12v) regulator - the cub was 6v originally. The points do not appear to be adjustable via any screws.

[John *.?-!.* cub owner]

There were 2 ways the power was applied to lights and ignition. Earlier ones were powered by a wire from the amp meter to the light switch. Later ones used the L lead of the regulator. Yours being a 65 should have the L lead wired though. The L lead is not used for charging though, that is done via the bat. terminal via a wire that runs to the starter., and there connects to the battery terminal lead.

[Astrowing]

As per the flow chart previously posted, make sure the regulator body is properly grounded. After my paint job, the generator quit charging. The problem was paint in the regulator mounting holes. I think corrosion could do the same.