Kohler — 15/20/25 Amp Charging System Test (no charge to battery)
Testing & diagnosis · battery charging system
From a Kohler service manual covering: CH18, CH20, CH22, CH23, CH25, CH620, CH630, CH640, CH670, CH680, CH730, CH740…. Check it applies to your exact model before use.
Applies to: Kohler CH18, Kohler CH740
Procedure
- Insert an ammeter in B+ lead from rectifier-regulator. Run engine at 3600 RPM, measure B+ to ground with DC voltmeter. If 13.8 V or more, place a minimum load of 5 amps on battery and observe ammeter.
- Remove connector from rectifier-regulator. With engine at 3600 RPM, measure AC voltage across stator leads using AC voltmeter.
- With engine stopped, measure resistance across stator leads using an ohmmeter.
- With engine stopped, measure resistance from each stator lead to ground.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- 13.8 volts or more
- 28 volts or more
- 0.1/0.2 ohms
- infinity ohms
Full service-parts list: Kohler CH740 →
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.