Use a digital multimeter across battery posts, everything off. The generic spec for a fully charged battery is 12.6 volts. Leave the leads on the battery posts, have helper turn key to crank. How far does the reading drop, shouldn't drop below 9 or 10 volts.
If you suspect a starter issue, some of the national brand autostores will test the starter for you. Take it off and take it to them for testing.
If you suspect hydrostatic lock, pull all the spark plugs, then try to crank.
It is possible your security system is causing an issue? You need to rule that out.
Saturday, March 6th, 2021 AT 6:07 PM
(Merged)