1. Check the Fuel Pump Relay:
* Location: Find your owner's manual or consult online resources (like a repair manual specific to your year and model) to locate the fuel pump relay. It's usually in the underhood fuse box or a separate relay center.
* Testing:
* Visual Inspection: Check the relay for any signs of damage (burnt contacts, melted plastic).
* Swapping: The best test is to swap the fuel pump relay with a known good relay of the same amperage rating (from a different circuit, like the horn or wipers – *never* swap relays without checking the amperage rating). If the problem moves to that other circuit, you've found your faulty relay.
* Continuity Test (Advanced): Using a multimeter, test the relay's internal contacts for continuity. Refer to a wiring diagram to determine which pins should have continuity in various states (relay energized/de-energized).
2. Check the Fuel Pump Inertia Switch:
* Location: This safety device cuts power to the fuel pump in the event of a collision. It's usually located under the dash, often near the driver's side kick panel, or sometimes in the engine compartment.
* Testing: Look for a small, usually red button on the switch. Push the button. If you hear a click, the switch is working. If pushing the button restores power to the pump, replace the switch.
3. Check the Fuel Pump Fuse:
* Location: Consult your owner's manual or online resources to locate the fuel pump fuse in the underhood fuse box (or possibly the interior fuse panel).
* Testing: Visually inspect the fuse for a blown element (broken filament). If blown, replace it with a fuse of the same amperage rating. If it blows immediately after replacement, there's a short circuit somewhere in the system.
4. Check the Wiring:
* Visual Inspection: Carefully inspect the wiring harness leading to the fuel pump for any signs of damage (chafing, fraying, corrosion). Pay close attention to the area near the fuel tank, as this wiring is prone to damage.
* Continuity Test (Advanced): Using a multimeter, test the continuity of the wiring between the fuel pump and the relay/fuse. Disconnect the wiring at both ends before testing to avoid shorting. A wiring diagram will be invaluable here.
5. Check the Fuel Pump (itself):
* Access: This usually involves dropping the fuel tank – a significant undertaking.
* Testing (Advanced): You can test the fuel pump directly with 12V power (be extremely careful with fuel!). If it doesn't run, the pump itself is faulty and needs replacement.
6. Check the Computer (PCM):
* Diagnosis: A faulty PCM (Powertrain Control Module) can prevent the fuel pump from receiving power. This requires professional diagnostics using a scan tool capable of reading codes from the vehicle's computer.
Important Safety Precautions:
* Disconnect the negative battery terminal before working on any electrical components.
* Work in a well-ventilated area when dealing with fuel systems.
* Never work near an open flame while working on fuel systems.
* Use appropriate safety glasses and gloves.
If you're not comfortable performing these tests, especially those involving electrical continuity testing or fuel tank access, it's best to take your Roadmaster to a qualified mechanic for diagnosis and repair. A simple relay or fuse replacement is relatively inexpensive; however, a faulty fuel pump or PCM can be significantly more costly.
