Step  | Action  | Value(s)  | Yes  | No  | 
|---|---|---|---|---|
1  | Using a test light, backprobe between the radio harness connector terminal F1 to ground. Is the test light on?  | --  | ||
2  | Repair poor connection or open in circuit 640. Is the repair complete?  | --  | --  | |
3  | Service the radio. Refer to Radio Replacement for service procedure. Is the repair complete?  | --  | --  |