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Home›Repair guides›Kohler›Voltage Regulator Board Test

Kohler — Voltage Regulator Board Test

Testing & diagnosis

From a Kohler service manual covering: 10RMOY, 15RMOY, 15RMY, 15ROY, 17.5ROY, 22.5ROZ, 22.5RZ, 24ROZ, 32.5ROZ, 32.5RZ, 47.5ROZ. Check it applies to your exact model before use.

Applies to: Kohler 15RMY, Kohler 15ROY, Kohler 17.5ROY, Kohler 22.5ROZ, Kohler 22.5RZ, Kohler 24ROZ, Kohler 32.5ROZ, Kohler 32.5RZ, Kohler 47.5ROZ

Before you start

  • High voltage present at regulator board P1 connector and terminal strip when set is running.
  • 240 Volts will shorten life of 120-Volt bulb.

Procedure

  1. Connect regulator board to a good SCR module as shown.
  2. Wire a 120 or 240-volt AC light bulb across (+) and (-) of SCR module.
  3. Wire on-off switch (open position) in series with AC power source.
  4. Wire 208-240 volts to V7 and V8 on terminal strip in regulator/terminal strip tray.
  5. Close switch to apply power; lamp should light.
  6. Adjust Pot. 2 to clockwise limit; adjust to counterclockwise limit to extinguish bulb.
  7. Connect battery (+) to P terminal and battery (-) to common wire between hourmeter and reset lamp.
  8. Turn on AC and DC power; adjust overspeed Pot. 5 counterclockwise until reset lamp turns on; return 1/8 turn clockwise.
  9. Reset fault; turn overvoltage Pot. 6 counterclockwise until reset lamp comes on; return 1/8 turn clockwise.
  10. If test indicates a faulty regulator board, replace and refer to new board adjustment procedure.

Tools required

Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.

Full service-parts list: Kohler 15RMY →, Kohler 15ROY →, Kohler 17.5ROY →, Kohler 22.5ROZ →, Kohler 22.5RZ →, Kohler 24ROZ →, Kohler 32.5ROZ →, Kohler 32.5RZ →, Kohler 47.5ROZ →

Source: Kohler service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.

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