New to me Cub - Couple of issues

[feg7846]

Brought home a nice 1969 yellow and white cub yesterday. Runs like a dream and hydraulics work great. It is also 12 volt and positive ground.

Couple of issues: Previous owner told me that if he leaves battery cables on, the coil gets hot even with ignition switch off. Said when he got through using it for the day, that he took battery cables off. I think he may have ignition switch wired wrong.

If I want to change it to negative ground, what is the process. It has a 12 v generator and a voltage regulator. Generator and voltage regulator are working fine, so at this point I do not want to change to an alternator. Has a gauge on it but don't know if it is ammeter or voltmeter. On the left side of the gauge is a D, on the right side is a C. I would assume this is for discharge and charge. When running, the gauge is showing a very good charge.

Is there anything else that you need to know from me in order to help me through this negative ground process?

Thank you, my friends

[Glen]

Hi,
Cubs made after mid 1964 are 12 volts negative ground.
Someone changed yours to positive ground, evidently.

You could turn the battery around, and connect it with negative ground, polarize the system, at the voltage regulator, and see if it works.

The battery should be in the battery box so both posts are on the left side, with the positive at the front.
It may have a battery with the posts in the wrong places, if someone bought a different number battery.

If it is an original IH gauge, it is an ammeter, the D means discharge, and the C means charge. I think the highest and lowest marks are 20 amps.

Below is the 1965 Cub operator's manual, the experts on here recommend reading it.
It has a table of contents on page 1. The index begins on page 75.

http://farmallcub.com/rudi_cub/www.clea ... index.html

Page 25 has a pic of the 12 volt battery in the battery box.
Page 32 tells how to polarize the 12 volt electrical system.
The manual has 6 and 12 volt info, disregard the 6 volt info.

I would check or change all the oils before using the Cub. Using it with low oil in a gear housing can damage the parts in the housing.
There are 3 separate gear housings, with 3 separate oil levels to check, in the rear area of a Cub, the transmission, and 2 final drives.

The transmissions in Cubs commonly get water in them, from rain, or condensation inside the housing over time.

The air cleaner is an oil bath air cleaner. Dirt that is sucked in settles to the bottom of the oil cup. It should have clean, light motor oil in the oil cup to work right.

[Don McCombs]

The first thing that I would do is to re-confirm that it is, in fact, set up as positive ground. Then work out the rest of the electrical issues.

[Eugene]

Couple of issues: Previous owner told me that if he leaves battery cables on, the coil gets hot even with ignition switch off. Said when he got through using it for the day, that he took battery cables off. I think he may have ignition switch wired wrong.

Easy check.

Roll engine over by hand until the TDC mark lines up with the pointer. Ignition off. Battery connected. Check for battery voltage from either coil terminal to ground.

[k hutchins]

FWIW
Years ago, in my ignorant youth, l accidently hooked my cub ( '48) up as neg ground. Couldn't figure out why the battery wouldn`t charge, and why l always had to hand crank it. It was that way for many years. After l learned, l simply swapped it back around. No extra fiddling with the generator or voltage reg. and it's been fine ever since.
Since your tractor was supposed to be neg ground anyway, how about you just swap it around and see what happens before you go extra steps that might not be neccesary.
Maybe others have previous experience with this, but what could it hurt?

[feg7846]

Is it necessary to swap the wires on the coil when converting to negative ground.

Thanks for all of the support cub owners. This site has helped me a lot.....

[Glen]

Hi,
Yes the wires at the coil need changing too.

With the negative ground system, the positive wire should come from the ignition switch, or the resistor, if the Cub has a separate resistor in the coil area, and go to the + post on the coil.

The short wire goes from the - post on the coil to the post on the side of the Battery Ignition unit.

I'm not sure if anyone said, if it has an ammeter, the wires need changing to the opposite posts or the ammeter will read backwards.