Re: 115 Volts drop when trying to start
Very likely that the battery cables are bad; they corrode inside the sheathing.
If you have a DC voltmeter you can easily isolate the resistance using a voltage drop test as follows:
So, put your positive voltmeter lead on the battery positive terminal and the voltmeter negative lead on the large incoming solenoid/battery terminal post and hit the starter switch. If the voltage meter reads more than .3 volts, the battery cable is bad, corroded or has a bad connection.
Next, connect the voltmeter negative lead to the outgoing large solenoid post and the positive voltmeter lead to the incoming large solenoid post while cranking the starter briefly. If the voltmeter reads greater than .2 volts, the solenoid is bad, corroded or has a bad connection.
Next, connect the positive voltmeter lead to the outgoing large solenoid post and the negative voltmeter lead to the starter positive post and hit the starter switch. A reading of over .2 volts indicates a bad wire between the solenoid and the starter.
Lastly, connect the negative battery post to the negative voltmeter lead and the positive voltmeter lead to the engine block and crank the engine. A reading of greater than .3 volts indicates a bad negative cable, corrosion or a bad cable connection.
The idea is that normally when you put both leads of a voltmeter on the same side of a circuit you should get no reading. If you have a reading, more voltage is passing through the voltmeter than through the circuit.
