Welcome! I’m not familiar with the 300EX but I did sleep at a Holiday Inn last month...
Did you take your battery to someone to load test it? How do you know it’s good?
The clicking tells me the low amp ignition system control circuit is complete—the clicking is the solenoid (relay switch for the high amp starter circuit) closing or trying to close.
Is the noise a chattering solenoid? Not enough power to keep solenoid closed. Then most likely bad battery or poor battery cable connection.
Is the noise a solid click and nothing until the starter button released? Indicates battery good enough to close solenoid but not enough to crank also maybe bad connection to starter, hung or bad starter or something else hanging up. Is there a kick or pull starter in this model?
If a hum and everything goes very dim most likely a bad solenoid
Did you take your battery to someone to load test it? How do you know it’s good?
The clicking tells me the low amp ignition system control circuit is complete—the clicking is the solenoid (relay switch for the high amp starter circuit) closing or trying to close.
Is the noise a chattering solenoid? Not enough power to keep solenoid closed. Then most likely bad battery or poor battery cable connection.
Is the noise a solid click and nothing until the starter button released? Indicates battery good enough to close solenoid but not enough to crank also maybe bad connection to starter, hung or bad starter or something else hanging up. Is there a kick or pull starter in this model?
If a hum and everything goes very dim most likely a bad solenoid
