Does anyone know why there are 2 solenoids on a F150? One on the firewall and one on the starter.

 

The one on the starter is a solenoid and the one on the firewall is a relay switch. A solenoid pushes or pulls a rod or actuator or both and a switch opens or closes a circuit.

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Yea, when you order a starter relay they call it a solenoid now lol. Not sure why, in the old days it was a relay and labeled that way. The starter solenoid piggybacked the starter in most cases.

These trucks have more than two solenoids, -I think of 5 of hand lol.

 

jberw,

Do you remember when the starter solenoid was called a Bendix?


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Yep lol, the "Bendix". I think there's a Bendix corperation as well or there use to be, -included brake parts and such.

 

I was told by an old timer, that the starter drive was actually the first invention of Bendix.

 

The "Bendix" is not the solenoid. The Bendix drive is the assembly inside the starter that engages the teeth on the flywheel and spins. The solenoid operates the Bendix.

 

Thanks folks. I had figured out that was it was a relay, but what all does it control.

 

The relay receives a low amperage connection from the ignition switch, that activates an electromagnet that makes contact for a high amperage wire to the starter. When the starter starts to spin, the centrifical force of the motor forces the starter drive gear into the ring gear, and starts spinning the engine.

 

I just bypassed the relay and it is working fine now. Will it cause any damage anywhere? Thanks