Kohler — PowerBoost III/IIIE Voltage Regulator Test
Testing & diagnosis
From a Kohler service manual covering: 10RFY, 10RFZ, 10RY, 10RZ, 12R, 12RFY, 12RFZ, 18RFY, 18RFZ, 18RY, 18RZ. Check it applies to your exact model before use.
Applies to: Kohler 10RY, Kohler 12R, Kohler 18RY, Kohler 18RZ
Before you start
- Do not touch voltage regulator heat sink when testing.
Procedure
- Connect variable transformer, AC voltmeter, regulator, and 120-volt lamp.
- Set variac to zero and plug in.
- Increase to 100 volts; lamp should light.
- Increase to 120 volts; lamp should go out.
- If lamp behavior fails, replace voltage regulator.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Lamp lights at 100 V; lamp goes out at 120 V
Full service-parts list: Kohler 10RY →, Kohler 12R →
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.