New guy issues. Scag 52 swz with Koehler 18

[StarTech]

Have check the resistance of the electric clutch coil? If partially shorted they can still operate but draw excessive current which overload the charging system. I seen these clutches to pull nearly 20 amps and still operate. Normal minimum resistance is around 1.7 ohms any below that indicates a shorting winding. Also most electric clutches pulls under 7 amps with 3-5 amps being closer to normal draw.

 

[bertsmobile1]

The body of the regulator is the ground connection
If it is mounted into the plastic blower housing , the mounting bolts need to have a ground strap to them
I make up 2 , one for each bolt .

 

[Bluegrassfj40]

Have check the resistance of the electric clutch coil? If partially shorted they can still operate but draw excessive current which overload the charging system. I seen these clutches to pull nearly 20 amps and still operate. Normal minimum resistance is around 1.7 ohms any below that indicates a shorting winding. Also most electric clutches pulls under 7 amps with 3-5 amps being closer to normal draw.

Clutch is brand new oem part. It is right at 3ohms resistance which seems to be right in spec according to the mfg.

 

[Bluegrassfj40]

The body of the regulator is the ground connection
If it is mounted into the plastic blower housing , the mounting bolts need to have a ground strap to them
I make up 2 , one for each bolt .

Good through. The housing is metal in this case. I don’t think I have a ground issue but could be wrong. I’ll check again.

 

[StarTech]

Clutch is brand new oem part. It is right at 3ohms resistance which seems to be right in spec according to the mfg.

Yes that would right. It was just a thought.

What is the AC input into the regulator? It needs to be at least 28 vac at 3600 rpm. If less than this then the stator is failing.

 

[lbrac]

Hey everyone. New here.
I have a couple dumb new guy questions.
- bought a used scag 52 swz with a kohler command pro 18.
- what powers the electric clutch? There is no battery on the mower. Is that normal?
- the clutch was not working when I got it. It failed the resistance check. I replaced it but the new part is also not engaging.
- checked voltage at the voltage regulator and it was 24v at full speed and 12v at low speed. So not working. Replaced that part but now it’s 12v at high speed and 3v at low speed and clutch still does not shift.

confused. Any help appreciated.

Were the voltage readings that you took at the regulator taken w/ with the clutch engaged? How do the resistance readings of the disconnected (wiring) clutches compare? Have you checked the voltage at/near the clutch w/ and w/o it engaged? Could be a switch or wiring issue.

 

[Bluegrassfj40]

Yes that would right. It was just a thought.

What is the AC input into the regulator? It needs to be at least 28 vac at 3600 rpm. If less than this then the stator is failing.When I measured across both stators it was in the mid 40’s. I think when I checked each on it was around mid to high 20’s. I can check again tomorrow.

 

[Bluegrassfj40]

Were the voltage readings that you took at the regulator taken w/ with the clutch engaged? How do the resistance readings of the disconnected (wiring) clutches compare? Have you checked the voltage at/near the clutch w/ and w/o it engaged? Could be a switch or wiring issue.

Voltages at the regulator were not taken with the clutch engaged.

 

[ILENGINE]

Has the replacement regulator been confirmed to be the 12 403 01-S or 12 755 111-S which is rope start only and not the 41 403 10-S or 25 403 37-S regulator which is for battery ignition.

Loose flywheel magnets can also give those types of voltage readings.

 

[Bluegrassfj40]

Here is another piece of info that may help diagnose. The mower has an ignition key switch on the panel but it has been forced to on so it does not require a key. Curious if that may indicate that this mower was once an electric start model…. I’m just not sure if they all came with keys even if it was a pull start (assuming not). Curious if the guy I bought it from pulled the starter and battery off of it, put a cord pull start thing on the top and sold it to em. Just a hunch. Thoughts?