[Excaliber]

Not alternator, as the battery seems to have a full charge, which is all the alt/gen does anyway. Engine running bat volts should be 13 + volts, maybe 14. At rest should be greater than 12 if not close to 13. If it's 15 or greater volts while engine running, suspect battery failure due to alternator regulator putting out to much volts, thus "boiling" over heating and damaging the battery.

Hot motors DO require higher amps to spin the starter than cold ones. Their are several ways to test the battery, heres a simple one. Get a GOOD volt meter (hope it's digital) and check battery voltage while attempting to crank the motor. It should NOT fall below 9.6 volts no matter what. If it does, suspect poor battery performance.

Weak starter is suspect, and more difficult to test without the right test equipement. You MIGHT be able to purchase an "induction amp meter" (they don't cost "that much" but are HARD to find). You hold it against the + battery cable while cranking. The current flowing through the wire "induces" a voltage in the meter and this is how it "reads" amps flowing. FOLLOW the directions for the meter carefully!

40-50 amps is high but in the ball park. Anything over that is suspect starter. There ARE specs for the amp draw of the starter, it could be as high as 75! A compotent automotive shop can run BOTH tests for a decent price to find out (IF you can find a shop that does that).

All this assumes that the vehicle USED to start fine, compression is not "to high", etc. This ALSO assumes you have verified GOOD CONNECTIONS to ground, battery terminals and starter terminal.

Ernie