Run a ground wire from the chassis or battery negative to .
Seat the F4901 expansion card into the designated backplane slot (usually adjacent to the F4900 Expansion A module 24V Power Hookup: f4901 11a 24v schematic install
terminal to a true earth ground to prevent the metal chassis from becoming "live" in the event of a fault. Run a ground wire from the chassis or battery negative to
Install a fast-acting fuse or a DC-rated circuit breaker (12A or 13A) upstream to protect the module from short circuits. Continuity Test: f4901 11a 24v schematic install
This is the most common point of failure for 11A units.