Warner Electric Electrical Evaluation - Manual (Page 2)

A. Symptom: Clutch will not engage
Problem Possible Causes Solution
- Blown fuse - Low coil resistance - Replace with new MagStop unit
- Defective battery - Replace
- Faulty charging system - Repair or replace
- Bad wiring or connections, PTO switch - Repair or replace
- Low voltage supply - Defective battery - Replace
(Less than 12 VDC at clutch) - Faulty charging system - Repair or replace
- Bad wiring or connectors, PTO switch - Repair or replace
- Incorrect coil resistance - Damaged coil - Replace with new MagStop unit
(see Step 1)
- Inadequate current supply - Broken clutch lead wire - Repair
- Faulty electrical system - Measure clutch coil resistance
and supply voltage at the clutch. If
both are correct, electrical system
is faulty. Repair or replace.
- Rotor/armature airgap too large - Rotor/armature wear. End of usable life - Replace with new MagStop unit
(greater than .125 inch/3.18 mm
B. Brake will not engage
Problem Possible Causes Solution
- Armature/brake poles wore out - End of usable life - Replace with new MagStop unit
- Contaminated friction surfaces - Engine oil leak on brake - Repair leak
- Replace with new MagStop unit
C. Clutch slip
Problem Possible Causes Solution
- Low voltage supply - Defective battery - Replace
(less than 12 VDC at clutch) - Faulty charging system - Repair or replace
- Bad wiring or connectors, PTO switch - Repair
- Inadequate current supply - Broken clutch lead wire - Repair
- Faulty electrical system - Measure clutch coil resistance
and supply voltage at the clutch. If
both are correct, electrical system
is faulty. Repair or replace.
- Overloaded clutch - Clogged deck, bad spindle, etc. - Remove excess grass
- Replace spindle
- Contaminated friction surfaces - Engine oil leak on clutch - Repair leak
- Replace with new MagStop unit
D. Symptom: Noisy clutch/Vibration
Problem Possible Causes Solution
- Failed bearing - Loose mounting (bolt not torqued properly) - Replace, torque to spec.
- Field assembly movement restricted - Confirm proper Anti-rotation
- Adapter plate rattles against - Some noise is normal - If noise is excessive, repair or
anti-rotation pin pin replace anti-rotation device.
(Follow OEM’s Specifications.
- Clutch loose on shaft - Loose mounting (bolt not torqued properly) - Tighten mounting bolt to specification.
- Mounting bolt too long and bottoms - Use correct length bolt
in engine shaft before clamping clutch
- Mounting washer too thin and
deforms when bolt is tightened.
- Shaft bottomed on D-drive - Use proper spacer 1/4" thick min.
- Clutch not mounted square - Ground Drive Spacer mounting shoulder - Replace
not square
- Clutch integral key hitting end of keyway - Space clutch away from radius
in engine shaft in shaft keyway.
- Incorrect or no chamfer on ground - Increase chamfer on ground drive
drive spacer. spacer.
- Broken spring - Loose mounting - Replace clutch
A clutch with broken rivets or springs may separate from the shaft and cause personal injury.
Troubleshooting Checklist
Warner Electric Commercial MagStop Clutch/Brake