Fuel Gauge Always Indicates Empty (Dual Tank Diesel)
- Disconnect fuel pump balance module connector. Turn ignition on. If fuel gauge reads full, go to step 3. If fuel gauge still reads empty, go to next step.
- Remove IPC. Using DVOM, check continuity of Purple wire between IPC harness connector terminal No. 16 and fuel pump balance module harness connector terminal "F". See Figure. See WIRING DIAGRAMS . If continuity exists, replace IPC. If continuity does not exist, repair Purple wire and retest.
- Using DVOM, check resistance between fuel pump balance module terminals "E" and "B"(secondary tank), and "E" and "C" (primary tank). If resistance is not between zero ohms (empty) and 90 ohms (full), go to next step. If resistance is between zero ohms (empty) and 90 ohms (full), go to step 5.
- Disconnect suspect sending unit harness connector. Check resistance between sending unit terminals "A" and "D"(secondary tank), and/or "A" and "B" (primary tank). If resistance is not between zero ohms (empty) and 90 ohms (full), replace sending unit. If resistance is between zero ohms (empty) and 90 ohms (full), repair open in wiring between fuel pump balance module and suspect sending unit.
- Check continuity between suspect sending unit harness connector terminal "A" (Black/White wire) and ground. If continuity does not exist, repair wiring or connector. If continuity exists, replace fuel pump balance module.