The PTC fuse controls the EFE relay.
Labeled "1", the EFE heater warms the air/fuel charge coming from the throttle body, and aids 'cold start' efficiency. It is not a vital component, but may set a check engine light.
-MechanicMatt
__________________
1996 Caprice 9c1 - Daily Driven Project Car
1993 Geo Metro - Accident
1991 Caprice 9c1 - Destroyed
