By maintaining a consistent millivolt signal

allowing for more accurate readings without requiring 3-wire or 4-wire compensation in many applications

ensuring maximum surface contact and heat transfer

you should typically see 10-14 mV under a normal closed-circuit load when connected to the gas valve magnet operative

rather than a faulty switch itself

Fenwal 05-129892-124 Harness By maintaining a consistent millivoltThe Fenwal 05 129892 124 wiring harness is a critical field service component designed for seamless integration with Series 05 12 ignition modules. This 24 inch assembly features 1 4 inch quick connect terminals, ensuring high integrity electrical pathways for gas fired heating systems. When troubleshooting HVAC ignition control wiring, technicians require a harness that maintains low resistance continuity to prevent nuisance flame signal dropouts.