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First time post, hope it goes well. I've got a strange charging problem w/ my Cub Cadet 1440 w/ Briggs Vanguard 14 V Twin. Alternator checks out, regulator checks out (actually new OEM). Tractor maintains charge with nothing on. Turn on lights or Pto and the Charge light comes on and battery starts draining. (Checked with Fluke DVM). If I take the Red output wire from the Regulator directly to the battery + terminal, the battery voltage immediately starts coming back up. Of course the charge light is still on. Anyone know what is between the regulator output and the battery that can be bad that isn't allowing current to flow? I haven't got wiring diagram for the tractor. This problem has slowly gotten worse over time. At first speeding up the engine caused the light go off, not anymore! Also, before the lights weren't a big enough drain, now they are. I'm currently charging battery between mows to keep 'er going. Next, I'll probably jumper straight from regulator to battery until someone can help me or I figure it out.

WELCOME to LMF...

Have you had this mower long enough to know the wiring is still factory? Some one may have modified things along the way...
If you are relatively sure the wiring is correct, You need to measure the charge circuit for any resistance, You may find a fuse or a fusable link in the line that is causing some resistance... :smile:KennyV

smaywork said:

I've got a strange charging problem .. Alternator checks out, regulator checks out (actually new OEM). Tractor maintains charge with nothing on. Turn on lights or PTO and the Charge light comes on and battery starts draining. ... This problem has slowly gotten worse over time. At first speeding up the engine caused the light go off, not anymore! Also, before the lights weren't a big enough drain, now they are.

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You know, it really sounds like a corroded connection somewhere that's at the heart of your problem. The corrosion has gotten worst over time, resulting in a high resistance connection to the battery. If it were me, I would back-tract along every connection trying to eliminate that contingency. (Could also be hidden, ignition switch contacts (inside switch) for example. Also carefully check where the black battery ground wire attaches to the frame.

Cub GT is totally original. I'm second owner and purchased from the original dealer. I suspect either the ignition switch or a diode is in the circuit, but can't confirm it w/o wiring diagram. Seems they put diodes everywhere and maybe there is one to keep from bleeding back? Rectifier in the regulator should do that, but who knows. The Ground I doubt because the thing starts like a scream when the battery is at full charge. Of course all wiring is in bundles, so I'd have to just start disconnecting/reconnecting to chase wiring. It's not killing me now, I was just hoping maybe someone else had the same issue. I've always wondered why the ignition switches on these mowers have, like, 6 terminals. Seems like 3 should be enough!

Kenny, you've got good Idea, I didn't think of disconnecting the battery positive and measuring resistance back from the regulator output to the Battery +. That would also tell me if it goes through the ignition switch also. I'm two weeks away from the problem now, but I'll check that when I get back. Thanks,

smaywork said:

The Ground I doubt because the thing starts like a scream when the battery is at full charge.

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Umm, I'd still consider it. When the battery is at full charge, it's developing 12-14 volts. But when charging, a high resistance will develop a voltage drop across the resistance, lowering voltage. And of course, to charge a battery, you must have a higher voltage than the battery to force the juice back into it.

But, then a direct connection from the regulator output to the battery + makes it charge fine. Thus, if there is a resistance, it must be in the Hot Side, not the Ground side......I'll disconnect and reconnect anyway, just to verify. Thanks

smaywork said:

But, then a direct connection from the regulator output to the battery + makes it charge fine. Thus, if there is a resistance, it must be in the Hot Side, not the Ground side......I'll disconnect and reconnect anyway, just to verify. Thanks

Click to expand...

I just found the electrical wiring schematics for the Cub 1440. if you want them, give me your email address (better put in coded form, IE "dot" instead of ".", etc) & I'll send a PDF of them (2 pgs).

From what I see, red wired off the alternator, through a diode, to the starter. Off the starter (heavy red wire) to the starter solenoid. Off Solenoid (heavy red wire) to battery.

To test diode.......

I got the PDF thanks enigma-2...:thumbsup:

Looking at the wiring I would test the diode first, come back and report.

I believe the diode that Enigma-2 was referring to is different than the one shown in your "diode check" attachment. My Cadet is a 1994 with the higher output alternator that doesn't have the diode in the wiring. If the diode that he is referring to was bad, the starter would want to run any time the ignition was turned on. I'm 200 miles away from the machine right now, so I'll continue to troubleshoot when I get back in a couple of weeks. I believe the alternator on this machine is a 16 or 20 amp output. It actually requires a genuine automobile battery, not the little 275 / 300 amp hr. that many mowers use. I always thought that strange, be then again, the battery lasts about 6 years also, not 2 like the others. Thanks a bunch for the help, especially the schematic. Unfortunately the schematic shows a "alternator", not a Stator, Rectifier, Regulator which is actually the case. Probably because this is a Cub Cadet schematic and not a B&S and Cadet. Once I find the solution, I will report it....

If you wanted help with engine, you should have posted up the engine/type numbers, that way we here know what you have...! so please post them, that way it will help us to help you.

Sorry, I thought I had made it clear that the stator / alternator / rectifier / regulator all work fine. The problem exist between the output of the regulator and the battery. Again, if I jump straight from the output (red) of the regulator to the Battery +, the battery charge voltage jumps right up to near 14 volts and maintains with both pto and lights on. So, I assumed (maybe wrong) the engine as a problem.

Also, as I mentioned, I am nowhere near this machine at this time and won't be for a couple of weeks, so, I can't do any additional testing or get any additional information off of the mower.

When I get back I will post more status updates. As for now, my hands are tied.

Thanks, I'll be back later,

Ok, Got home and started the GT and mulched leaves w/ the red charge light on. When I got done, I took the side off, the battery out, and went straight to the ignition switch. I pulled the connector off and she wasn't pretty. Sprayed contact cleaner (electronic contact cleaner) in the connector and put it back together. Then I had nothing, no juice period. Took out the ignition switch and checked for resistance and sure as can be the resistance across the R-B contact was metering around 140-160 ohm. I had another switch, but doesn't match the grounding magneto type switch. So, I bent the shut off tab (M) over and put the switch in. Now, the tractor starts, runs and charges fine. However, the lights are on all the time. So, I pulled the bulb connector to the headlight and I have to "choke" it to kill it until I can find the proper switch. So, now does anybody know the p/n for the 6 contact, 4 position (Off, On w/lights, On, Start) switch? I hate to go back to the dealer and get socked for another $40 (after they talked me into a new regulator for $65.

You will find your switch here: Lawn Mower Ignition Switch 12752 Replaces. Cub Cadet 725-3163, 925-3163 | eBay
or here: R12752 Ignition Switch Replaces Cub Cadet 925-3163
or here: Parts and Diagrams for Cub Cadet 1440 S/N 821,060 - 880,000
Your temporary fix is okay, But I don't like using the choke to kill an engine....
:smile:KennyV

In the mean time put a Rocker switch or Push to make switch between the kill wire that you took off the key switch and earth, that way you will stop the engine right, and not choke it to death.

Well,

I just realized the safety switches (seat and pedal) will shut it down around the ignition switch. Good news, bad news is that while I was troubleshooting I think I trashed the starboard side magneto, because now, I'm only running on one cylinder. I've got no spark at all to the one cylinder. I believe I put 12 VDC to the magneto when I tried using the alternate ignition switch.

All I needed was the mower to last one more leaf collection season, and the death spiral started!

Funny how things progress,

Thanks for all your help, I think I'm going to call somebody to pick up my leaves this fall. I don't have the time to pull the engine and replace a coil.

I have the same simptoms. I would like to hear from you when it gets solved! Thanks, PaJohn7007