Possibilities to start with: coil/s, module, plugs, wires, injectors,ecm & wiring.
If you get a single "Click" the first time Check for dirty or loose battery terminals, check wires on solenoid, or replace solenoid
If you are talking about the fuel shutoff solenoid then there are two wires
Big cable from the battery goes to the big post on the solenoid. Solenoid will have two small posts one with an S one with an R. (Start side, relay side) largest of the small wires goes to the start side smaller of the two small wires goes to the r side. if there are three wires hook both the smaller wires to the r side. The larger of the small wires is usually always the start wire and is purple in color.
Usually battery or solenoid. If you hear a clicking noise, it is the solenoid. find the red wire coming off the battery, follow it until it connects to the solenoid, take off the red and black wires, put new solenoid in and your done.
Jump the wires on the starter solenoid - Jumper wire connected the large cable running to the starter and the smaller "trigger" wire The solenoid in most vehicles today is located ON the starter. If you attempt the aforementioned answer, BE CAREFUL.
You don't NEED it exactly its just a fancy box that connect your battery wires to the starter. If your lawnmower is clicking/wont start or silent when you turn the key its possible its the solenoid. undo the rubber covers from the solenoid touch the two bolts together using something metal and start it up, bam. you just by-passed the solenoid. (the solenoid will be next to the starter in most cases and have two rubber wire covers on them)
cut the wires and the new solenoid will have the part to solder the cut wires together
To connect the wires on a 1986 Ford F150 solenoid, start by removing the negative battery cable, then connect the wire from the ignition switch to the "S" terminal on the solenoid. Next, connect the wire from the starter to the "I" terminal on the solenoid. Finally, reconnect the negative battery cable. Be sure to consult a wiring diagram specific to your vehicle for accurate connections.
First locate bad solenoid. Once you have found it, unscrew wife nuts and disconnect the black wires from the other wires. Then simple unscrew the solenoid... Do all this with sprinkler system off
the solenoid is on the starter. It's the part the wires go into.
The starter solenoid? Attached to the starter. Round thing, wires, etc.