Mower problem

My Mom has a 17 year old John Deere riding mower. 20 HP runs like new....till the other day. Went down again this past weekend to mow and it just wouldn't start. Battery was completely dead. If you jump start it, it'll run all day, no problems. But now, if you shut it off, wait about 10 seconds and restart, it does fine. Wait 3 minutes and it's dead. Won't even click. I have a couple of ideas about what's wrong, but I thought I'd run it by you guys and see what you think.

Alternator/stator, whichever system that uses. Most likely the regulator is shot, they go bad. Testing can be found in places like the attached:

a reply to: HalWesten

Voltage regulator ? Cause that's what I was thinking. The battery is not charging and seems to drain when it's not running, like it's grounded somewhere, but I spent an hour chasing wires and couldn't find anything wrong.

Gotta go to work. Be back later to check in. Thanks in advance for your advice.

Check the owner manual for required maintenance. If it runs on a jump the battery is bad if you don't see any wiring issue. I had a similar issue with a car. Ended up being the sun visor light. It wasn't going off when closed. Drained the battery.

That too. Batteries don't last very many years. You can take that to an autoparts store and they will check it with a load tester.

a reply to: DAVID64

If the battery is charged and it won't turn or click:

Solenoid is bad (if you can jump/bridge the solenoid and it starts, that's the problem).
Starter is bad.
Ignition switch is bad.

For starters.

These are the (only) problems I've had with my Craftman, which is about...15ish years old. That damned ignition switch took me forever to figure out.

Get the manual
Take top of the engine off
Clean the flywheel and the "magnets"
But , most likely a battery.

has everyone replying to this - actually read the OP ?

just curious

I would replace battery and go from there. I just had a motorcycle battery do the same thing. Wouldn’t hold a charge. I could jump it and ride all day but park it and try an hr later and it wouldn’t have the power to turn over the bike. You may have a dead cell.

Battery.

“Wait 10 seconds it will restart” fully lubed and hot engine with some power still in the battery, just enough power and the motor is red hot, course it will start

Check your wiring is tight, check it’s not dirty, loose connections are a killer but
As stated over and over, battery, if it jump starts fine then it’s poor connections or battery

I'd start with battery. Always, always clean air filter, can be clogged with grass.

Could just be the battery or it could be the alternator diodes or regulator. I think those would have the starter/alternator in one unit if I remember correctly. It could be a coroded wire or connection somewhere too, I can usually tell what things are from multiple symptoms that occur, you only have a couple listed. How fast it turns over is important too to try to evaluate it

Make sure all leads are tight and not corroded. If not, then it's most likely bad cell, like already mentioned.

If you want to do some diagnostics on it, you can get a cheap clamp style no-contact capacitive load tester online that will tell you all kinds of stuff fast.
When everythings off, put around hot from battery to see if there is a parasitic drain/short somewhere.

Then observe voltage gain when you start it on same positive lead wire to test stator/alternator output.
Test with DC amp load setting.
You can just clamp tester around wires throughout the ignition system to see if relay or whatever is bad, just follow down the line from battery, through relay, to starter testing each segment for Amps as you go.

If you can get it running again check the charging system.

With the engine running test the battery leads with a multimeter to see if you have close to 14 V. It can't be 10, 11 or 12 or even 13. It needs to read at least 13.84 or better.
13 V might work but its not enough to burn head lights on a car very long.

That will tell you if your charging system is bad or good and usually that leaves only the battery providing all connections are good

Another thing batteries very seldom last past 4 years. Its almost like they have a death clock built in.
I saw one set go 7 years and have never seen it again.

a reply to: Trucker1

just too add to this - the alternator diode pack - can go haywire and overcharge - which kills batteries just as ffast - 14.4 is pretty much max - if its above 14.8 - then it will be the alternator -

and on the subject of alternators - the diode pack - the little plastic bit held on the rear - 2 screws - can often be replaced - as a " bodge fix " - if thealternator bearings etc are all servicable

thats my secret tip for today - it doesn always work - and its no subsitute for a recon alternator

but when you are sitting in a puddle - contemplating a 2 hour job - banging a new pack in and seeing what happens - is the way forward - at least it gets the vehicle in service - and proper maintanance can be done at next service schedule

Come on now. It needs a battery, mine only lasts about two years. I have a zero turn, 25 hp, and just had to put another one in it a few weeks ago.
Pretty much everybody prorates them if they go bad within 2 years.
I started putting a trickle charger on mine and it keeps way better and fires right up.

The big problem now is the crappy ethanol fuel rotting the lines, spark plugs, and messing up the carburetor.

Lawn mower batteries are guaranteed for 90 days now. They were 2 years. Then 1 year. Now only 90 days. I just bought one myself.