48 Farmall C battery draw?

Was wondering if anything other than leaving the ignition or lights on can cause a battery draw on a Farmall C. I put a brand new 6 volt bat. in about 4 weeks ago and it was stone dead today. I am charging the battery to test it but was wondering if anything else can cause this. Thanks

Points in the Voltage regulater can stick...

Like Dalex said, the regulator would be a good place to start.

Can also be corrosion growing on any connection that is always connected to the battery, like the back of the ignition switch, amp meter, light switch, etc. It can also be inside a switch or amp meter, especially if it sits outside.

The same can happen with old,frayed, or rat chewed wiring. It can corrode and leak through the insulation.

There are all sorts of minor (higher resistance) shorts that might drain a battery other then leaving lights or ignition on. One common cause is where a wire has bad insulation and the worn spot is touching steel, so take a good look for such things.

Now, if when the tractor is shut off the ammeter swings over to a high discharge that will drain a battery very quickly. Such may be caused by a sticking cutout relay. If that happens the generator will get hot and in fact if you loosened the belt it would spin and the battery discharges very quickly if that happens. When you turn the tractor off the GEN/ARM terminal (one that wires to gennys ARM post, NOT up to ammeter) on a Cutout Relay or a Voltage Regulator should read 0 volts to frame ground, if it stays hot after shut down, the cutout relay is sticking closed.

Of course, a battery can be bad and discharge on its own even if the tractor and all else is fine.

John T

As far as a possible stuck closed cutout relay, after shut down if you remove the wire to GEN/ARM on the Voltage Regulator or Cutout Relay and then touch it back in place THERE SHOULDNT BE ANY SPARK, if it sparks when you touch it to the GEN/ARM terminal the relay may well be stuck closed, an ammeter if it has one swings to high discharge, gennys gets hot (would spin if belt loose) battery discharges quickly. Also as I noted below, after shutdown there shouldnt be voltage on the GEN/ARM terminal.

John T

Disconnect the wire on the "A" terminal of the generator. Then check it for power. It should not have any power with everything turned off. If you check it with it hooked up to the generator you may not get a reading even if there is voltage there because it will be going thru the generator to the frame/ground thus using up all the voltage.

Dear John, with all due respect (Im here to help NOT argue) and only to help clarify things a bit. You say "check it with it hooked up to the generator YOU MAY NOT GET A READING even if there is voltage there because it will be going thru the generator to the frame/ground thus using up all the voltage."


With specific regard to "you may not get a reading even if voltage is there"

Its my professional (albeit a tad rusty lol) opinion

If voltage IS THERE (on ARM terminal if its wired to gennys ARM post) due to the cutout relay closed (connects BAT to GEN/ARM), you WOULD GET A READING of approximately battery voltage with respect to frame ground. The BAT terminal is wired to the battery perhaps via a series ammeter, and if the relay is closed BAT is connected to GEN/ARM, SO YOU "WOULD GET" A READING APPROXIMATELY WHAT THE BATTERY VOLTAGE IS


With regards to your statement "using up all the voltage?"

It is my professional opinion

"Indeed, the battery voltage will be dropped mostly ACROSS the generator if its in the series circuit from battery due to a closed cutout relay. THERE WOULD BE BATTERY VOLTS ON THE GEN/ARM TERMINAL IF THE RELAY IS CLOSED and its all dropped (you call used up) across the Generator, thereby you end up at zero volts on the gennys grounded brush output which is connected to frame ground. Its all got dropped (used up) across the load which is the generator. BUT THERE IS A READING AND ITS APPROXIMATE BATTERY VOLTS AT THE START, WHICH IS THE GEN/ARM POST if the cutout relay is closed (then gets dropped across the genny)

SOOOOOOOOOOO what I'm saying is that if the VR or Cutout Relay is in place and all wired correct and the Cutout Relay is stuck closed:

You WOULD GET VOLTAGE (with respect to frame) on the GEN/ARM terminal since its essentially connected to the battery via the ammeter and closed cutout relay

Most all that voltage gets dropped (you call used up) across the Generator but at the starting point GEN/ARM terminal its there since that's basically connected to the ungrounded battery post via an ammeter and a stuck closed cutout relay (it connects BAT to GEN/ARM if closed)

Hope this helps and again Im NOT here to argue but only help with all due respect.

John T Too long retired EE and rusty so no warranty but I still believe Kirchoffs laws and voltage drop principles apply?? But Ive been wrong manyyyyyyyyyy times before lol