Open Positive?

sano888

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Usually these regulators are the 12/15 half wave amp version. So I would fuse at @15 amp.

And yes most DIYers usually go a little over board but that is normal. Just shows lack of experience. Heck many shops do the same thing as they also lack electrical experience and knowledge. But I do have now have 45 yrs of experience doing it so I am little more into the testing stages.
Have no idea what 12/15 half wave amp means. Did try a 15A and it blew right away.
 

StarTech

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If it blew the fuse right away you got a dead short somewhere to ground.

First make the PTO is off and then try. The current draw in run position would the fuel solenoid normally which is only a few amps.. If fuse holds then engage the PTO clutch. if the clutch is half way fine then the fuse holds otherwise it will blow the fuse. Note PTO clutches normally pulls less than 7 amps.

Also note that a shorted regulator will blow the fuse as soon as you the the key to run position according the RTZ wiring diagram.
 

ILENGINE

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If it blew the fuse right away you got a dead short somewhere to ground.

First make the PTO is off and then try. The current draw in run position would the fuel solenoid normally which is only a few amps.. If fuse holds then engage the PTO clutch. if the clutch is half way fine then the fuse holds otherwise it will blow the fuse. Note PTO clutches normally pulls less than 7 amps.

Also note that a shorted regulator will blow the fuse as soon as you the the key to run position according the RTZ wiring diagram.
Just to add that a shorted to ground stator can also cause the fuse to blow because one of the AC terminals on the regulator is bridged to the B+ terminal.
 

sano888

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So I put the fuse in. Started right up. Put the shroud back on, fuse blows. Take the shroud off, change fuse, starts right up. Though maybe one of the bolts was grounding it out or something. Lay the shroud on while running, fuse blows. Figured out that where the carb is connecting to the wiring harness, the connection was being pushed up against the heat shield for the cylinder. Moved the wire, secured it, shroud on, started right up. Always something.

However, with engine running, multimeter is only reading 12.45 at the battery. Got a feeling the recharge problem is not fixed.
 

StarTech

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Well either way you are making progress even if it is two steps forward and one step back.

Recharging problem depends on the standing battery voltage before starting vs running voltage. If the running voltage is above the standing voltage give it a few minutes to see if it starts climb voltage wise but no more than 14.5 vdc.

And you may still a failed voltage regulator if the stator AC output is within spec. 28 VAC or higher then the stator is fine.
 

Fish

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Unplug the wires and do a reading of the two wires from the alternator. Should read @ 28 volts AC at full speed.
 

sano888

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Well either way you are making progress even if it is two steps forward and one step back.

Recharging problem depends on the standing battery voltage before starting vs running voltage. If the running voltage is above the standing voltage give it a few minutes to see if it starts climb voltage wise but no more than 14.5 vdc.

And you may still a failed voltage regulator if the stator AC output is within spec. 28 VAC or higher then the stator is fine.
Agree. Making progress. At least now I know what's where and can assume that parts are in proper working condition. Glad I got it cleaned out under the flywheel if nothing else. Will start the testing process over at some point. For now, I'll keep charging the battery after each use. Will give updates as I return to this project. Need to move on to pruning. Thank you for the help.
 
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