Troubleshooting a Charging Problem

Sat Jan 03, 2004 4:45 pm

My'50 Cub has quit charging. I have polarized the generator and the ammeter moves when I turn on the lights, but other than that, the ammeter reads - 5 amps at all engine speeds. Can you guys help me by giving me a troubleshooting list to isolate the problem. The service manual is no help at all.

Many thanks as always.

Sat Jan 03, 2004 10:22 pm

Rick, go to this link and look at the last 2 photos on the page. They are Bob Melville's troubleshooting diagrams.

Sun Jan 04, 2004 8:44 am

Thanks, big Dog. That is exactly what I was looking for. It will go right to the front of my Cub reference book.

I will post what I find.

Many thanks.

Wed Jan 05, 2005 9:30 pm

Rick Look at picture 12 you will see that term 3 has the headlights and term 2 is the tail light. The unnumberd term is used internal to the switch. My understanding is the red tail light and work light were run off the same wire, with a switch at the rear for the work light. 1 wire to the tail light from the switch in the dashboard. A ground wire was terminated locally near the light. I have heard the work light switch was part of the light and also that it was seperate.
In some of the later models a seperate tail light and work light wire were run as well as a ground wire terminating at or near the dash board. Bob Melvill's sketches do not cover that possibility. I have also heard of a flasher unit somewhere in the rear for the red tail light. If only I could remember where I hear things or who told them to me. Can't be old age, I never could.
If it were me doing this for my self and I had the 2 wires I would wire the red tail light to term 3 with the head lights and the work light to term 2. If I had only 1 wire I would run a second or put a switch so that I could control the work light when the red tail light is lit. Lets face it the cub generators are low amperage and every amp generated is less power to the wheels. We lose sight of that with todays monster engines in cars tractors and trucks, Hundreds of horses. A cub is somewhere between 8 1/2 and 16 HP according to the year.
To our forefathers every little bit counted. Today we just use a bigger hammer.


Wed Jan 05, 2005 10:27 pm

beaconlight wrote:I have also heard of a flasher unit somewhere in the rear for the red tail light.

The flasher was for the warning light that was mounted on the long support that bolted to the left fender and stuck above the tire. The flasher mount was different depending on which seat the tractor had.