Kohler — Relay Board Replacement Procedure
Repair & overhaul · Optional relay board
From a Kohler service manual covering: 12RES, 12TRES, 8.5RES. Check it applies to your exact model before use.
Applies to: Kohler 12RES, Kohler 12TRES, Kohler 8.5RES, Kohler CH20 engine, Kohler CH 740 engine
Before you start
- Accidental starting can cause severe injury or death.
Procedure
- Access the controller junction box to locate the relay board.
- Disconnect relay board harness connector P3 from connector P14 on the relay board.
- Pull the faulty relay board off the four mounting standoffs.
- Press the new relay board onto the four standoffs.
- Connect three-pin connector of harness GM52639 to P14 on relay board GM51403.
- Verify harness is securely connected to P11 on the control board and to the engine harness.
Full service-parts list: Kohler 12RES →, Kohler 12TRES →, Kohler 8.5RES →
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.