View Full Version : is the battery bad, or is the alternator?
Montehall
05-04-2011, 2:42pm
My mower usually starts without a hitch.
even after being outside all winter I was able to just crank it over for the first mow of the season.
I tried it yesterday, and it started, ran for a few minutes, then died. When I tried to start it again, it would barely crank. So I hooked up the car jumper and it fired right up, ran for a minute, then died.
The battery is only 5 months old.
http://img.photobucket.com/albums/v257/Wilson1911/focus/2011-03-26_16-11-04_562.jpg
Stangkiller
05-04-2011, 2:44pm
My mower usually starts without a hitch.
even after being outside all winter I was able to just crank it over for the first mow of the season.
I tried it yesterday, and it started, ran for a few minutes, then died. When I tried to start it again, it would barely crank. So I hooked up the car jumper and it fired right up, ran for a minute, then died.
The battery is only 5 months old.
http://img.photobucket.com/albums/v257/Wilson1911/focus/2011-03-26_16-11-04_562.jpg
Use a Volt Meter to see what you're producing when it's running vs off.
I am gonna suggest the alternator needs to be checked out,
themonk
05-04-2011, 3:04pm
Do an AVR test, that'll tell ya.
navyndi2
05-04-2011, 7:31pm
I am gonna suggest the alternator needs to be checked out,
:iagree:
Omega Man
05-04-2011, 8:17pm
are you sure it is an alternator and not a generator?
If it runs fine when hooked up to a good battery, then dies when you unhook it, then yes, it is bad.
Uncle Pervey
05-04-2011, 8:22pm
As Omega man said, If you start it and disconnect the battery and if it dies, then replace the alternator and charge the battery. :yesnod:
Y2Kvert4me
05-04-2011, 8:33pm
As Omega man said, If you start it and disconnect the battery and if it dies, then replace the alternator and charge the battery. :yesnod:Think he was referring to the battery. A good alternator/generator will keep an engine running even with a junk battery.
Disconnecting the alt while running is a (crude) battery test, but not much of an alternator test.
But once a known good battery is verified (easiest thing to sort out first), the fact the engine is dying more suggests the possibility of a direct short somewhere on the positive side...Shorted diode in alt can do this, a chafed wire shorting to ground anywhere on the non-fused + side can too.
:cheers:
Which one is the mower?
The Ford.
1911fool
05-04-2011, 9:11pm
Check and make sure the air in the tires is fresh. you may need to rotate the air.
Check and make sure the air in the tires is fresh. you may need to rotate the air.
Might need new muffler bearings too.
The Ford.
Question stands...........
Montehall
05-07-2011, 9:24pm
so I charged the battery overnight and was able to mow the whole yard.
Then I stopped, but it wouldnt restart... battery was dead. wouldn't even turn over, just "whir"
Uncle Pervey
05-07-2011, 9:44pm
Well that tells me that the alternator is bad, it doesn't take much voltage to fire a spark plug. You charged the battery, started it and mowed for a while. The battery discharged because the alternator was not providing any recharge for the battery. I have seen it many times in all sorts of vehicles.
If you would have kept mowing long enough it would have completely flattened the battery and it would have died. :yesnod:
Well that tells me that the alternator is bad, it doesn't take much voltage to fire a spark plug. You charged the battery, started it and mowed for a while. The battery discharged because the alternator was not providing any recharge for the battery. I have seen it many times in all sorts of vehicles.
If you would have kept mowing long enough it would have completely flattened the battery and it would have died. :yesnod:
http://www.pawsru.org/f/src/f113885_I%20Concur%20Gorilla.jpg
Tank's
05-07-2011, 10:23pm
http://www.pawsru.org/f/src/f113885_I%20Concur%20Gorilla.jpg
no need of obama pic :slap:
mrvette
05-08-2011, 7:23am
Well that tells me that the alternator is bad, it doesn't take much current to fire a spark plug. You charged the battery, started it and mowed for a while. The battery discharged because the alternator was not providing any recharge for the battery. I have seen it many times in all sorts of vehicles.
If you would have kept mowing long enough it would have completely flattened the battery and it would have died. :yesnod:
Now just the other day, on my neighbors garden tractor, he did not have the usual 'alternator/generator' on the thing.....the battery is recharged alright, off the same sort of flying magnet mounted to the flywheel, as runs the spark....
trick is, that puts out a pulse on a coil, that pulse goes to a custom regulator chip on the shroud of the engine, with a heavy wire going to the battery.....the chip has a diode in there to rectify the a/c pulse, and a regulator to keep the charge rate correct...
found it with my DVM really easy....the input wire had a/c voltage on it, and no output to the battery.....only one thing home in between, it's about 2" wide, and 1.5" high....4 wires on a plug as I recall....2 screws....damn thing cost Bob 65 bux.....bastards....
I trying to remember the maker of the engine, I want to say Kohler.....but not sure....
:cheers:
Montehall
05-08-2011, 10:39am
Now just the other day, on my neighbors garden tractor, he did not have the usual 'alternator/generator' on the thing.....the battery is recharged alright, off the same sort of flying magnet mounted to the flywheel, as runs the spark....
trick is, that puts out a pulse on a coil, that pulse goes to a custom regulator chip on the shroud of the engine, with a heavy wire going to the battery.....the chip has a diode in there to rectify the a/c pulse, and a regulator to keep the charge rate correct...
found it with my DVM really easy....the input wire had a/c voltage on it, and no output to the battery.....only one thing home in between, it's about 2" wide, and 1.5" high....4 wires on a plug as I recall....2 screws....damn thing cost Bob 65 bux.....bastards....
I trying to remember the maker of the engine, I want to say Kohler.....but not sure....
:cheers:
This mower has a kohler, but there is definetly a belt-driven alternator/generator there.
mrvette
05-08-2011, 11:47am
This mower has a kohler, but there is definetly a belt-driven alternator/generator there.
Seems odd, sure it's not a starter instead??
trying to remember how Bob's starter appeared.....sorry been a couple months now...
:cheers:
I am gonna suggest the alternator needs to be checked out,
Don't they just use the starter kind of like a reverse motor to charge the battery?? I don't think there's a separate alternator.
lallend
05-08-2011, 4:06pm
This mower has a kohler, but there is definetly a belt-driven alternator/generator there.Try this...
- Even though the battery terminals may appear clean and tight, disconnect, clean and re-tighten the terminals.
- Find where the negative battery cable goes to ground, disconnect, clean and re-tighten.
- On the alternator, disconnect, clean and re-tighten the wires.
- Look hard at the Alternator belt. Is it cracking, glazed or even tight? It could be slipping (and not even making noises)...
Please take care of those maintenance items before ya go out buying battery's, alternators etc etc
mrvette
05-08-2011, 5:20pm
Try this...
- Even though the battery terminals may appear clean and tight, disconnect, clean and re-tighten the terminals.
- Find where the negative battery cable goes to ground, disconnect, clean and re-tighten.
- On the alternator, disconnect, clean and re-tighten the wires.
- Look hard at the Alternator belt. Is it cracking, glazed or even tight? It could be slipping (and not even making noises)...
Please take care of those maintenance items before ya go out buying battery's, alternators etc etc
Sure as hell ain't no lawnmower, BUT on my motor home project, the CS144 alt V belt was slipping like a frozen lake.....and silent too.....
but the alt would not put out when the inverter hit the fridge....
voltage would dive like a dolphin,......inverter would go ape shit and shut down....drove me krazy for a while....
until I had my DVM on the correct test point in the wiring, open the hood, modify the mount a bit, tighten living HELL outta that belt...and sure enough....
how in hell a fan belt can slip and not make NOISE is beyond ME....
:shots::leaving:
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