battery light when pto switched on

jimmysisson · Sep 13, 2011

My 1994? Cub Cadet 1440 is solid and dependable. That said, when I switch the pto on for the deck, the battery light stays on for maybe 6-8 minutes, then goes off. Headlights on won't make that happen, unless the battery is weak. I replaced the pto clutch maybe 40 hours ago (total ~500 hours now). Anyone know why this might happen? No other symptoms I can see.
Thanks, Jim

bullbreaker · Sep 13, 2011

jimmysisson said:
My 1994? Cub Cadet 1440 is solid and dependable. That said, when I switch the pto on for the deck, the battery light stays on for maybe 6-8 minutes, then goes off. Headlights on won't make that happen, unless the battery is weak. I replaced the pto clutch maybe 40 hours ago (total ~500 hours now). Anyone know why this might happen? No other symptoms I can see.
Thanks, Jim

I would start by starting it with another battery but would avoid buying a new one.
If not start it up with another battery with jumper cables attached to your battery and start and see if light comes on with other battery in line.
If battery on another vehicle,tractor,etc do not start other motor. I believe the pto switch is or does pull more than lights on.Just a thought.

Boone

jimmysisson · Sep 14, 2011

Thanks. My CC starts just fine - would the second battery just provide backup amp-hours? I'm not sure if the pto switches on any other circuit. I know the pto switch itself is questionable. It tends to kick off when I first switch it on, and I have it held up with a rubber band to the throttle lever. Hmm, maybe that's the problem - a poor contact through the switch? Except that the light blinks and the electric pto clutch stays engaged. Maybe I'll try a new switch and see what happens, since I need one anyway.
Jim

Carl_NH · Sep 30, 2011

I dont have a battery light but an ammeter on my 1811, but early this year I was mowing and the PTO just stopped when mowing. Come to find out the battery wasnt holding a charge due to dead cells after 8 years even tho it was getting 14.5 V charging.

After I replaced the battery no more problems. Most auto parts stores will test it for free and I bought a new battery at autozone for $40 - the old one wouldnt even register on the tester it was so dead.

the switch also might have a weak contact so replace the switch and test the battery.

whiskywizard · Sep 30, 2011

I'm unfamiliar with your specific year/model, but in this class of tractor and mower most PTO switches are very similar; when you operate that switch (close it) you send power to a large electric solenoid that engages a drive clutch. That solenoid, all by itself, is a substantial electrical load and it will tax a charging system if it isn't in top condition.

As mentioned above, you might need to check the condition of your battery. Most auto parts jobbers will do this for free. If it passes a load test, you'll also need to test the charging system to rule out the alternator/voltage regulator.

But before you do any of that, check the condition of the cable connections. A poor connection can cause a voltage drop. Chekc at the battery (both -ve and +ve), at the engine block ground, and at the starter and starter solenoid. Then check the smaller wires at the PTO solenoid/clutch. If they are all good, clean and tight, then pull the battery and load test it.

Likely it is the battery - an inexpensive fix you can do easily yourself.