Ford 7.3 Godzilla Starter Relay Location: Fix Stuck Starter Issues in

The Rundown

WARNING: Always disconnect the negative battery terminal before working in the engine compartment to prevent electrical shock and accidental short circuits.

For your 2022 RV with the 7.3 Godzilla engine, the starter relay is located in the engine compartment fuse box (also called the Power Distribution Box or PDB). On Ford chassis with the 7.3L engine, this is typically positioned on the driver's side of the engine bay near the firewall. The starter relay is usually labeled as "STARTER" or relay position R1 and is a standard 4-pin relay. Your diagnosis appears correct - a stuck starter relay can cause the starter to stay engaged after the engine fires up, which can damage the flywheel ring gear and trigger crankshaft position sensor codes, putting your RV into limp mode exactly as you've experienced.

The good news is this is typically a straightforward fix that costs around $15-25 for a replacement relay. Before replacing it though, you'll want to check the relay socket connections and verify the ground circuit, as you mentioned suspecting a grounding issue. Poor connections can cause relays to stick or fail to release properly.

Why It Happens

Starter relays fail in several ways, but the "sticking closed" failure you're experiencing commonly happens when the relay contacts weld themselves together due to excessive current draw or arcing. Common causes include a failing starter motor that's drawing too many amps, corroded relay socket connections creating resistance and heat, or simply normal wear after thousands of start cycles.

When the relay contacts stick closed, the starter continues receiving 12 volts even after you release the key, causing it to stay engaged with the spinning flywheel. This creates a horrific grinding noise and can quickly damage the starter drive gear and flywheel ring gear teeth. The excessive mechanical stress and unusual rotation patterns can confuse the crankshaft position sensor, triggering the P0016, P0017, or similar codes that put your 7.3L into limp mode.

Your grounding theory is also valid - if the relay's ground circuit has high resistance due to corrosion or loose connections, it can cause erratic relay operation. The relay may not fully energize during cranking or may not fully de-energize when you release the key, leading to intermittent sticking behavior.

Gather These Items

• Replacement starter relay (correct part for your model - verify with dealer - or equivalent 40-amp 4-pin relay, approximately $15-25)
• Digital multimeter with continuity and voltage testing capability
• Wire brush or sandpaper for cleaning corroded connections
• Dielectric grease to protect connections after cleaning
• Basic hand tools (pliers, screwdriver) for removing the fuse box cover
• Contact cleaner spray for cleaning the relay socket
• Small flashlight or headlamp for inspecting connections
• Spare fuses in case you discover other issues while testing

The Fix

WARNING: Disconnect the negative battery terminal before beginning this repair to prevent electrical shock and accidental short circuits.

Start by locating the Power Distribution Box on the driver's side of your engine compartment. Remove the cover and locate the starter relay using the diagram on the underside of the cover or in your owner's manual. Before removing anything, take a photo of the fuse box layout for reference.

With the engine off and key removed, carefully pull the starter relay straight up from its socket. Inspect the relay terminals for corrosion, burning, or melting. Examine the socket connections inside the fuse box - look for green corrosion, burnt plastic, or loose terminals. If you find corrosion, clean it with a wire brush and contact cleaner.

1. Test the old relay by swapping it with an identical relay from another position (like the A/C clutch relay if it's the same type). If the starter problem moves to the other system, you've confirmed a bad relay.
2. Check socket voltages: With the relay removed, you should see 12 volts at the control circuit terminal (usually position 85 or 86) when the key is turned to START - if assistance is needed for testing, ensure all personnel maintain safe distance from electrical components. You should also have constant 12 volts at the power terminal (position 30). Verify all voltage readings are within acceptable range and connections are secure.
3. Test the ground circuit by checking continuity between the relay ground terminal and a good chassis ground. You should have very low resistance (close to zero ohms).
4. Install the new relay and test the starting system. The starter should engage only while cranking and immediately disengage when you release the key to the RUN position.

If problems persist after relay replacement, check the starter solenoid connections directly on the starter motor. A failing starter solenoid can mimic relay problems and may need replacement as well.

Know Your Limits

This repair is well within DIY capabilities for most RV owners and typically takes 30-60 minutes to complete. However, if you're uncomfortable working around the engine compartment or don't have a multimeter to properly test circuits, have a qualified RV technician handle the diagnosis and repair.

Be aware that continuing to operate with a sticking starter can cause expensive damage to your flywheel, starter, and potentially your engine's crankshaft position sensor system. If you hear any grinding noises during or after starting, stop immediately and don't drive until the issue is resolved. The limp mode your RV entered is a protective measure, but continued operation could lead to more serious engine damage.

If replacing the relay doesn't solve the problem, or if you find evidence of burnt wiring or melted components in the fuse box, seek professional help immediately. These symptoms could indicate deeper electrical issues that require professional diagnosis and repair to prevent potential fire hazards or more extensive damage to your RV's electrical system.