Handle the heavy current your starter motor needs with the Standard Motor Products Starter Solenoid / Relay SS-581 (also written SS581). It is an electrically operated switch that connects the battery to the starter motor when the key is turned to start. It fits many vehicles, among them the 1975-1979 Ford F-150 4.9L / 5.0L / 5.8L / 5.9L / 6.4L / 6.6L / 7.5L, 1964-1973 Ford Mustang 2.8L / 3.3L / 4.1L / 4.3L / 4.7L / 5.0L / 5.8L / 6.4L / 7.0L and 1953-1979 Ford F-250, and is a direct-fit replacement for the listed applications.
Standard Motor Products classifies this part as a Starter Solenoid, and its product title reads Relay, so it is listed under both names. The catalog lists it for a fender-mounted position.
- Function: A small current from the start circuit energizes the coil. This closes the contacts that carry high current from the battery to the starter motor.
- Position: Fender mounted, as cataloged.
- Quantity: The listed applications use one.
- Engine coverage: On the 1975-1979 Ford F-150, listed engines include the L6-4.9L, V8-5.0L and V8-5.8L. The "Vehicles it fits" section has the rest.
Signs this part may need replacing include a single click with no crank, intermittent starting, and a starter that keeps running after the key is released. A weak battery, corroded cables or a faulty ignition switch can cause the same symptoms, so test the starting circuit before you replace anything. If a failed solenoid is the cause, the SS-581 replaces it. Shopping for a 1953-1979 Ford F-250 starter solenoid? The "Vehicles it fits" section lists every vehicle and engine this part fits.
Frequently Asked Questions
Is this the right 1975-1979 Ford F-150 4.9L / 5.0L / 5.8L / 5.9L / 6.4L / 6.6L / 7.5L starter solenoid?
It is listed for the 1975-1979 Ford F-150, including L6-4.9L, V8-5.0L and V8-5.8L engines. Check your year and engine in the "Vehicles it fits" section.
Will it work as a 1964-1973 Ford Mustang 2.8L / 3.3L / 4.1L / 4.3L / 4.7L / 5.0L / 5.8L / 6.4L / 7.0L starter solenoid?
Yes. It is listed for the 1964-1973 Ford Mustang 2.8L / 3.3L / 4.1L / 4.3L / 4.7L / 5.0L / 5.8L / 6.4L / 7.0L and also for the 1953-1979 Ford F-250. The "Vehicles it fits" section shows the other listed vehicles.
What does a starter solenoid do?
It is an electrically operated switch. A small current from the start circuit energizes its coil, which closes contacts that carry high current from the battery to the starter motor.
Why is this part also called a relay?
The catalog classifies SS-581 as a starter solenoid, and its product title reads Relay. Both names describe a switch that controls the high-current starter circuit.
What are the signs a starter solenoid may be failing?
Look for a single click with no crank, intermittent starting, or a starter that keeps running after the key is released. Test the battery, cables and connections first, because they can cause the same symptoms.
