It could be that there is a bad connection between the starter solenoid and the starter, or that the starter motor itself has failed. Check the wires first. They're cheaper to replace.
This also happens when the battery is very low, so it may be worth charging the battery if you haven't already eliminated that possibility.
this probablly because you have a flat battery or your start motor may be wrecked.
your battery is dead or the starter solenoid
Usually when a starter solenoid/relay switch is bad, you will hear only a click and the starter will not spin (crank).
The single click, that you hear when the starter switch is operated, is the solenoid making the high tension connection to the starter motor. If the starter motor doesn't turn over, you will need to check both the battery feed to the solenoid and the feed from the solenoid to the starter motor (this is typically a short length of braided cable). I have known this cable to corrode through. If it has, the easiest remedy, is to replace the entire starter motor.
Bad starter is easy: when you turn the car on provided your battery is good, you will hear a click in the engine compartment, but the car will not start.
It is either the solenoid or the starter is shot
your battery is dead or the starter solenoid
you can try to short the starter motor . take a screw driver and bridge ffrom battery cable on starter to ignition wire on starter. if starter is good, engine will crank. if starter is bad , solenoid will click if no clicking, solenoid is bad
Good power all the way to the starter, 12 volts at solenoid/start circuit wire when key engaged, but no click or starter engage
You need to replace the starter solenoid .
Batteries don't "click," but other parts do. If you're hearing that "click," it's probably the starter solenoid trying to engage. Either the battery's charge is low, the starter solenoid has failed, or the starter motor itself has failed. On some older cars, especially Fords, the "click" could also be a remote starter relay.
the solenoid on your starter is finished, replace the starter......
If the battery and starter check out good and you are only getting a single click, the problem lies in the starter solenoid or relay. Not sure where the relay might be but the solenoid is usually where the positive battery from the starter connects to. There are at least two wires at the solenoid - the battery cable and a thin wire. check the remote starter solenoid usually monted on right side of engine bay
Sounds like starter solenoid is going bad and needs replacing
The battery is dead, the connection is bad, the terminals are corroded, the starter is bad, the solenoid is bad.
battery almost dead or bad solenoid.
check battery, check solenoid, check starter
This sounds like your starter solenoid is bad.