Electrical Problem

[bob]

Bought a used Husqvarna Z246 zero turn with Briggs Model 40U477 Endurance Series engine. Problem was not charging and burning smell. Replaced stator with a used one I had and replaced regulator with aftermarket one and still burning smell. Checked stator and found black and burnt so I knew were smell was coming from. Order new stator and it came with regulator. Put it on could still smell a burning smell. Took flywheel off and check stator again and burnt again. Started checking voltage hopefully before I destroy another stator. No load on regulator (disconnected at connector). Stator is 30vac and voltage regulator at about 13vdc. This is mid range throttle. Connect regulator up and stator voltage drops to 8-9vac. I have checked with meter for shorts to ground and I see none. Check all connectors for burnt signs, see nothing, tried a different battery even though it is new, same. I put an ammeter on where fuse sits and show about 8 amps which isnt that high. It is not blowing fuse. All of my test are with no PTO engaged and actually I disconnected wires at PTO. I am looking for any help or suggestion before buying another stator. I am also assuming that the stator is good since it measures 33vac with no load. Thanks

[KE4AVB]

Disconnect the carburetor fuel solenoid, remove it, and install a temporary bypass with bolt [screw] of the proper size and thread pitch. IF it is a Nikki it is a M8-100. I haven't size the Walbro or Ruixing fuel solenoids.

[bob]

Just checking that you didn't reply to wrong post. You really want me to disconnect fuel solenoid for my problem?

[bgsengine]

It IS part of the electrical system - it is a solenoid that is powered by battery voltage with key on, possible for it to be failing or shorted (if you have a spare handy, could swap them out) however, It is also possible KE4 mis-posted because I don't think I have ever seen a solenoid failure causing so much of a current draw that it would overload the stator. (Unless it is backfeeding ground through stator, but then read on...)

OTOH, if it was me, I would start by carefully checking grounds Try running a jumper wire directly from bare engine block somewhere to the battery negative post, which would bypass all grounds except voltage regulator body ground.. IF voltage regulator is mounted to plastic engine shroud, the body does need to be able to touch bare ground... some had jumper ground wires from body bolt to engine block when mounted into nylon/plastic engine shroud, but others did have a through bolt that threaded into the engine block. Only other thing that could be causing stator to burn out like that would have to be applying 12v DC directly to one of the alternator wires... so you may want to check your wiring harness to verify that something has not been mis-wired that way as well... or perhaps someone swapped in the wrong ignition switch (Again which would cause mis-wiring, without messing with wiring...)

[KE4AVB]

I have seen them shorted pretty bad; just may not reached the point of blowing the fuse yet. Also have seen the solenoid power to be pinched between the starter and crankcase and would only short when enough was able break the then insulation. Usually after the crankcase warmed up.

Either way there something that really pulling current when the engine is running. Beside the stator are generally max out at around 13-15 amps and are not designed to do this all the time. And this particular mower has a 20 amp fuse

[Arkie]

Question:
Are you saying the STATOR AC voltage drops from 30Vac to 8-9 volts AC when you connect the regulator to the stator AND NO dc LOAD IS CONNECTED TO THE REGULATOR??

If the above is what you are saying your after market regulator itself is now shorted or the wrong one. The reason it's burning out the stator and not blowing the DC 20a fuse is the overload is before the fuse, the AC output of the stator is overloaded at the regulator itself.

To protect the stator from burning again you need to fuse the stator AC leads (both AC leads) with a 3-5 amp fuse to protect the Stator's overload. This fusing is just temporary stator protection until you get the problem corrected. With the DC load disconnected from the regulator the AC stator load should be typically less than 1 amp. When the stator AC VOLTAGE DROPS FROM 30 to 8-9 volts the stator's AC output is overloaded and is going to burn fast.

Can you post up a wiring diagram of your rig? (or a link to such)

[bob]

No it is when I connect a load to the voltage regulator the stator voltage drops. With the regulator and stator connected but not to a load the stator voltage measures 33vac and the output of voltage regulator measures about 13vdc. everything looks good. It as soon as I connected the output of regulator to circuit everything drops. This would appear i have a short somewhere but I can not see anything and yet it does not blow a 20amp fuse either. I still wonder if the stator or voltage regulator is at fault or when it is under a load but I cant keep trying new parts plus waiting for a new part to come

If you want to look at schematic, just google "Husqvarna z246 operator manual" and download. That is all I can find. I do not think Husqvarna offers a service manual which would help a lot

[KE4AVB]

Here is something that might help and keep from burning up the new stator and regulator. This provided you have a fuse holder available. Just wired it in the output lead of the regulator and installed a 10 or 15 amp fuse. ATC fuses are cheap to replace especially when you buy them in lots of 50 from Amazon.

[Arkie]

I would also temporary fuse the AC stator wires and install a 5 amp or so fuse right at the regulator output.

When you see that stator voltage drop from 30 volts to 8vAC that is a clue it's going to burn.
i WOULD ALSO TEMP REDUCE THE 20 amp fuse to around 5 amps so as to try and get a hint as to the direction of the OL.

You need to keep fuses in the stator AC leads to keep from constantly smoking the stator.

Without the pto en-gauged the only major load amps NORMALLY would be battery charging amps B

Another hint so as to troubleshoot with even using your engine's stator's AC. Get a 120 volts to 24V control transformer like is used in HVAC control voltage, just connect it's two output 24 leads to your regulator and test W/O even having to run the engine. Fuse the transformer with a 3-5 amp fuse and have a AC voltmeter monitoring the 24 volts when you apply voltage.

Like KE4 says get a pocket full of ATC fuses and fuse holders. Do not use the breakers in this case they might re-act too slow.

[KE4AVB]

I prefer to use an amp meter but most techs don't have high current amp meters laying around. I do have a 40/400 amp clamp meter here which can be use to troubleshoot problems like this. The problem may only exist with the engine running. But I would testing the amp draw at the battery without it running and the ignition in run position. If a heavy amp draw from the battery then you know you have a partial short somewhere unrelated to stator/voltage regulator. Just note there is a remote (helper) relay in the wiring harness which doesn't show up in the IPLs. Husqvarna uses it to control the starter solenoid (relay).

But the key here is careful patience troubleshooting. Not all problems easy from found especially when it comes to electrical problems. IF you find yourself getting frustrated just back away and try again later.

And just had an odd thought. What if you have wired the regulator to the starter side of the starter solenoid instead of the battery side. Can be easily done when replacing the starter solenoid. That would definitely cause excessive current draw with the engine running as it would trying to run the starter.