Generac — Test 32 - Test RPM Sensor
Testing & diagnosis
From a Generac service manual — check it applies to your exact model before use.
Browse Generac generators & specs →
Before you start
- DO NOT LOCATE THE SENSOR TIP CLOSER THAN 1/4 TURN FROM THE FLYWHEEL
Procedure
- Gain access to the control console interior; connect an accurate AC voltmeter across terminals 79 and 0.
- At engine cranking speed the meter should read approximately 0.4 to 0.6 volt.
- Use a VOM to test sensor resistance.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Older sensors should measure about 130 ohms ± 10%
- Newer sensors should measure about 1,000 ohms ± 10%
Source: Generac 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.