Generac — W Style: Switch Will Not Retransfer to Utility

Testing & diagnosis · Contactor Assembly (W)

From a Generac service manual — check it applies to your exact model before use.

Browse Generac generators & specs →

Procedure

1. Remove cover on contactor assembly.
2. Set multimeter to ohms. Measure coil resistance and compare to chart.
3. Measure resistance between J2-1 and J2-3. Closing coil resistance should be measured. Refer to chart.
4. If proper values not measured, replace transfer coil. If proper, proceed.
5. Remove screw from PCB and unplug harness. Manually transfer to standby position if needed.
6. Measure resistance between blue and brown wires on female side of plug. Less than 1 ohm. If not, replace LS1 (0D4516).
7. Measure resistance between yellow and brown wires. INFINITY. If not, replace LS1 (0D4516).
8. With contactor in standby position, measure resistance between green and gray wires. Less than 1 ohm. If not, replace LS2 (0D4516).
9. Measure resistance between green and gray wires. INFINITY. If not, replace LS2 (0D4516).
10. Plug PCB harness back in. Measure resistance between T1 (Red) and T2 (White). Less than 1 ohm.
11. Measure resistance between A1 (Blue) and T1 (Red). Less than 1 ohm.
12. Measure resistance between A1 (Blue) and T2 (White). Less than 1 ohm.
13. If any readings greater than 1 ohm or INFINITY, replace time delay limit switch. If all favorable, replace PCB (0D7400).

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.

More Generac repair guides →