LX178 Voltage Regulator Replacement

[bethel178]

I have an LX178 Lawn Mower that I bought new in 1992. It has mowed my lawn and pulled a small trailer occasionally.
The charge light comes on erratically now and I thought it just needed a new battery but the new battery did no change anything. I have went over the wiring looking for loose connections but have found none.
I am thinking the voltage regulator needs replacing and I can't figure out how to get at the nut side of the two bolts holding the regulator in place. The panel just below the mower switch and headlight switch must need to come off but I am guessing.
Any help at what to take off to get at the voltage regulator would be appreciated.
Thanks!

 

[Roadworthy]

It could be the voltage regulator but it could just as easily be the alternator. If it's the alternator it could be something as simple as worn out brushes. Try to learn a bit more about your system before throwing more money at it.

 

[Richard001]

You engine does not have a brush type alternator. The charging coil lies underneate the flywheel.

As Roadworthy said, do some testing first before your start putting in new parts.


Here is some info from the FD440V shop manual.

Do this, first, with the engine stopped and the on/off/start switch in the off position, take your voltmeter, set it to VDC and measure the battery voltage.

Compare the voltage reading to the note below:

A fully charged cell at 80 degrees F would show a specific gravity of 1.265. If all six cells are fully charged, an accurate digital voltmeter reading of battery voltage would show 12.68 volts.

Specific gravity for a 50 percent discharged cell would drop to 1.19 and battery voltage would fall to 12.24.

When specific gravity reaches 1.12, the cell is fully discharged and battery voltage falls to 11.89 volts, assuming the specific gravity is the same in all six cells.


If you battery is showing fully charged or nearly fully charged, then you need to check the output of the charging system. To do that, with your meter still set to DCV, start the engine and then rev up the engine. The voltage on your battery should increase to about 14.5V. If not, proceed to the next test.

Here is a drawing of the charging coil, note that there are two leads coming from the coil.

Follow these instructions to determine if your charging coil is working.

 

[Gator6x4]

It could be the voltage regulator but it could just as easily be the alternator. If it's the alternator it could be something as simple as worn out brushes. Try to learn a bit more about your system before throwing more money at it.

Don’t believe a LX178 has an alternator. The LX178 has a stator.

 

[Richard001]

bethel178​

Have you had a chance to make these measurements ?

Let us know what you have found.

Richard