Does The RV Fuel Vault cover both diesel and DEF on my Seneca?

Yes. It covers and secures both the diesel fuel cap and the DEF cap in one armored enclosure.

Will it fit every Seneca floorplan?

Yes. Every Jayco Seneca and Seneca XT is built on the Ford F-550 chassis with the same filler configuration. Fits all floorplans.

I already have a locking fuel cap. Do I still need this?

A locking cap only covers your diesel filler. Your DEF tank is still completely exposed. The RV Fuel Vault covers and locks both in one enclosure.

How long does installation take?

8-15 minutes with basic hand tools. No drilling, no cutting.

Limited Lifetime Warranty plus a 30-day satisfaction guarantee.

Built for the Seneca

Jayco Seneca Locking Fuel Door — The Part Jayco Left Off

The Jayco Seneca is Jayco's flagship Super C — built on the Ford F-550 with the 6.7L Power Stroke diesel. But like every Super C, Jayco left the diesel and DEF caps completely exposed. The RV Fuel Vault is the exact-fit armored locking enclosure your Seneca needs.

The RV Fuel Vault — Jayco Seneca — locking fuel door for motorhomes

The Problem

✖Your Jayco Seneca has exposed, unlocked diesel and DEF caps — Jayco does not include a fuel door
✖The F-550 Power Stroke carries 50-80 gallons of diesel worth $250-$400 — a theft target
✖DEF contamination from tampering can destroy your emissions system — $5,000-$10,000+ to repair
✖A locking fuel cap only covers one filler — your DEF tank is still completely exposed
✖Exposed filler necks attract road grit and diesel splash-back that damages your paint

The RV Fuel Vault Solution

Factory-finished look — eliminates exposed diesel and DEF caps on your Seneca
Precision-engineered for the Jayco Seneca on Ford F-550 filler neck configuration
Tamper-resistant keyed lock secures both diesel fuel and DEF fluid simultaneously
High-strength fiber-filled polymer — built to match your Seneca's quality
Bolt-on in 8-15 minutes — no drilling, no cutting, no modifications to your Jayco
Corrosion-proof construction rated for year-round full-time RV use

See the Difference

✖ Exposed caps on Seneca — no security

✓ RV Fuel Vault installed — sealed and locked

Why You Need a Locking Fuel Door

Lead with finish. End with security.

Factory-Finished Look

Eliminates the exposed plastic caps on your Seneca. Your rig finally looks factory-complete.

Fuel Theft Prevention

Keyed lock stops siphoning at campgrounds, rest stops, and storage facilities.

DEF Contamination Defense

Prevents tampering with your DEF tank — avoids catastrophic $5K-$10K SCR system repairs.

Vandalism Protection

Tamper-resistant design deters opportunistic damage to your fuel system.

Installs in 8–15 Minutes — No Drilling, No Cutting

8–15 Minutes

Average install time

Basic Hand Tools

No special equipment needed

100% Reversible

No drilling, no cutting, no mods

Compatible Ford F-550 (Jayco Seneca) Motorhomes

The Jayco Seneca is built on the Ford F-550 with the 6.7L Power Stroke diesel. Both diesel and DEF filler necks are completely exposed from the factory — the same gap every F-550 Super C has.

Manufacturer	Models / Floorplans
Jayco Seneca	All floorplans on Ford F-550 (37K, 37TS, etc.)
Jayco Seneca XT	All floorplans on Ford F-550
Also fits other F-550 Super C	Entegra Accolade XT, Dynamax Force HD/DX3

Don't see your model? Use the Fitment Finder — we likely fit your rig.

Frequently Asked Questions

Common questions about The RV Fuel Vault on Ford F-550 (Jayco Seneca) motorhomes

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Order Today — Starting at $99.95

Single Door, Set of 2, or 3-Pack · Free Shipping · Limited Lifetime Warranty · 30-Day Guarantee

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Proudly Made in the USA · Patent Pending 64/085,223 · Est. delivery by July 4, 2026