LX178 Electrical System-Charging

[Shimon]

First of all you need to test the battery voltage while the engine is running at speed. It should be 13V -14.5V. If it is then you probably have a bum battery...have it load tested.

If the battery light on the dash is not lit when the engine is running then the stator is putting out AC to the voltage regulator/rectifier. If the battery light is lit then the problem is with the stator and/or permanent magnet. Or the battery light/circuit may be bad. Put 12V to the positive lead of the light to test the bulb and ground circuit.

Check the 15A fuse on the circuit board which provides voltage sensing to the regulator.

You can test stator output by unhooking the 6 pin connector from the voltage regulator and test for AC voltage at pin 4 & 6 (brown/white & brown/yellow). With engine running at speed should see minimum 26VAC.

But it doesn't sound like the stator is bad because you never mention the light.

So, I would guess that you have corrosion somewhere on the wiring (check those grounds!) or you have a battery problem.

Until we know battery voltage while the engine is running at speed...it's hard to say anything. Invest in a decent digital voltmeter if you don't have one. If you don't know how to use one, take the machine to a JD dealer because proper electrical troubleshooting is not easily explained.

 

[thl]

The battery is definitely not charging. I removed the battery and charged it. And then did a load test. Battery tests good.
When running in the mower it will gradually lose charge. This AM the voltage at the battery was 11.65.
I tested the stator and I'm getting about 34 VAC. The ground at the regulator also tests good.
Is there any type of impedence check that can be done on the pins of the regulator?

Thanks,

Terry

 

[Shimon]

The battery is definitely not charging. I removed the battery and charged it. And then did a load test. Battery tests good.
When running in the mower it will gradually lose charge. This AM the voltage at the battery was 11.65.
I tested the stator and I'm getting about 34 VAC. The ground at the regulator also tests good.
Is there any type of impedence check that can be done on the pins of the regulator?

You can't test the regulator directly because it's a solid state device. At least I don't know how without having the proper parameters and data for the device...plus you would need an o-scope.

If you have good AC voltage at the stator (sounds like you do with 34 VAC) and you don't have good output DC voltage from the voltage regulator/rectifier then you have a bad voltage regulator.

Before condemning it, I would check the voltage at pin 1 and 3 (red and black wires) while the connector is still connected to the voltage regulator and the engine running at speed to be sure the problem isn't in the wiring closer to the battery. I wouldn't use any other ground except the one at the connector while testing. Also, check that you have actual battery voltage at pin 2 (yellow/black) which is the voltage sensing wire feeding the regulator.

Assuming all the wiring is ok (tests above come out ok), it looks to me like you need a new regulator.

 

[Shimon]

The battery is definitely not charging. I removed the battery and charged it. And then did a load test. Battery tests good.
When running in the mower it will gradually lose charge. This AM the voltage at the battery was 11.65.
I tested the stator and I'm getting about 34 VAC. The ground at the regulator also tests good.
Is there any type of impedence check that can be done on the pins of the regulator?

I notice that you are not the original poster. Are you having the same problem that CaptMarion is having?

 

[thl]

I notice that you are not the original poster. Are you having the same problem that CaptMarion is having?

After reading the veneralbe Captian's first post I would venture to say YES. For the last year or two I've been doing much the same. I keep a trickle charger next to the mower's parking space and simply charge it before using. I've been avoiding the cost of the regulator until I was more convinced that it is the problem.

 

[thl]

You can't test the regulator directly because it's a solid state device. At least I don't know how without having the proper parameters and data for the device...plus you would need an o-scope.

If you have good AC voltage at the stator (sounds like you do with 34 VAC) and you don't have good output DC voltage from the voltage regulator/rectifier then you have a bad voltage regulator.

Before condemning it, I would check the voltage at pin 1 and 3 (red and black wires) while the connector is still connected to the voltage regulator and the engine running at speed to be sure the problem isn't in the wiring closer to the battery. I wouldn't use any other ground except the one at the connector while testing. Also, check that you have actual battery voltage at pin 2 (yellow/black) which is the voltage sensing wire feeding the regulator.

Assuming all the wiring is ok (tests above come out ok), it looks to me like you need a new regulator.

Shimon,

I did the last two tests. Tests came out ok.

I ordered a new one from Pat's Small Engine in MN. Received it today, just installed it and behold, the tractor is now charging.

Thanks for all your help,

Terry

 

[OliverArk]

I had the same symptom with my LX178, but the battery light would come on while mowing, if I moved the wires around near the regualtor the light would go out. Inspecting the wires at the regulator I found one of the terminals in the connector burnt. I removed the terminal from the connector and soldered a new one on, cleaned the terminal on the regulator and applied die-electric grease and works like a champ now. I think maybe age and vibration caused this.

 

[Snipe]

I hope that is what just happened to mine this evening. NO POWER any where though. Hadn't had time to look at anything yet. Fuses looked good.Running good light was flickering, touched harness and then nothing. Lost all power. Find more out Mon. a.m.

 

[Shimon]

I hope that is what just happened to mine this evening. NO POWER any where though. Hadn't had time to look at anything yet. Fuses looked good.Running good light was flickering, touched harness and then nothing. Lost all power. Find more out Mon. a.m.

If your battery voltage is good then it's a fusible link or a fuse or loose/bad connection.

 

[lexluther1971]

First of all you need to test the battery voltage while the engine is running at speed. It should be 13V -14.5V. If it is then you probably have a bum battery...have it load tested.

If the battery light on the dash is not lit when the engine is running then the stator is putting out AC to the voltage regulator/rectifier. If the battery light is lit then the problem is with the stator and/or permanent magnet. Or the battery light/circuit may be bad. Put 12V to the positive lead of the light to test the bulb and ground circuit.

Check the 15A fuse on the circuit board which provides voltage sensing to the regulator.

You can test stator output by unhooking the 6 pin connector from the voltage regulator and test for AC voltage at pin 4 & 6 (brown/white & brown/yellow). With engine running at speed should see minimum 26VAC.

But it doesn't sound like the stator is bad because you never mention the light.

So, I would guess that you have corrosion somewhere on the wiring (check those grounds!) or you have a battery problem.

Until we know battery voltage while the engine is running at speed...it's hard to say anything. Invest in a decent digital voltmeter if you don't have one. If you don't know how to use one, take the machine to a JD dealer because proper electrical troubleshooting is not easily explained.

I have the same charging issue LX178, however my light IS on and the stater is fine!! It tests 31.5 volts ac.

Your saying if its on the stater is bad, but this doesn;t seem the case. If I unplug the regulator the light doesn't come on, and while plugged up doesn't even get warm. Where is this 15 amp fuse?