Help your diesel light off on cold mornings with this Dorman relay, part number 904-194, a diesel glow plug relay that switches battery power to the glow plugs when the engine's control system calls for preheat. It fits many vehicles, among them the 1995-1996 Ford F-250, 2003 Ford E-350 Club Wagon and 2003 Ford E-450 Super Duty. See the "Vehicles it fits" section for the full list.
Dorman designed this diesel glow plug relay to install and operate like the original relay on the listed applications, and built it for durability and dependable performance. If a failed relay is behind your hard cold starts, this unit replaces it.
- Direct replacement: Built to match the original relay's fit and function on the listed applications.
- Ideal solution: A dependable replacement when the original relay is damaged or has worn out from fatigue.
- Durable construction: Made from quality components and intended for reliable operation over a long service life.
- Trustworthy quality: Backed by Dorman's team of product experts in the United States and more than a century of automotive experience.
Because weak glow plugs, damaged wiring or a control-circuit fault can cause the same starting symptoms, diagnose the glow plug system before replacing the relay, and follow your vehicle's service information during installation.
Interchange: RY-525
RY525 · AP63405 · GPR11 · F5TZ12B533A · F7TZ12B533AA · F7TZ12B533AB · F7TZ12B533C · F81Z12B533AA · F81Z12B533AC · 522009 · DY861 · 1826634C94 · 1831646C1 · 1R1878
This part cross-references / interchanges with the following part numbers:
AP63405, GPR11, F5TZ12B533A, F7TZ12B533AA, F7TZ12B533AB, F7TZ12B533C, F81Z12B533AA, F81Z12B533AC, 522009, DY861, 1826634C94, 1831646C1, RY-525, 1R1878
Frequently Asked Questions
What does a diesel glow plug relay do?
It acts as a switch that sends battery power to the glow plugs when the engine's control system calls for preheat, helping warm the combustion chambers for starting a cold diesel.
Will this work as a Ford F-250 relay for my 1995-1996 truck?
Yes. Dorman 904-194 is listed as a direct-fit replacement for the 1995-1996 Ford F-250, where it switches power to the glow plugs for cold starting.
Does this relay fit other Ford trucks and vans?
Yes, it fits many other Ford models, including the 2003 Ford E-350 Club Wagon and 2003 Ford E-450 Super Duty. The "Vehicles it fits" section shows the full list.
What are signs a glow plug relay may need replacing?
Hard or slow starting in cold weather, long cranking before the engine fires, or rough running and smoke right after a cold start may signal a glow plug system problem; the relay is one possible cause.
Should I test anything before installing the new relay?
Yes. Diagnose the glow plug system first, since failed glow plugs, damaged wiring or a control-circuit fault can cause similar symptoms. Follow your vehicle's service information when installing.
