Bert,
Here are a couple things that will help you in figuring out battery
charging/cranking problems. A fully charged battery in good condition
should read 12.6 Volts with the engine off and all assessories off. This
can be checked with a voltmeter connected between the negative and the
positive terminals of the battery. The alternator, if charging, should
raise that voltage with the engine running at an idle or maybe just a
little faster to 13.6 to 14.6 volts.(Voltmeter still connected on the pos
/ neg. terminals of the battery) This is regardless of assessories on or
off. The rule of thumb is 12.6 static battery voltage and 13.6 to 14.6
volts charging. If with the engine running you have 12.0 or lower to 12.6
volts you do not have an alternator participating in the program. If you
have even 13.2 your alternator is weak and needs attention. If your
alternator is not working upto voltage get it fixed before you worry
about anything else. I always suspect battery failure because it is so
often the case. If you don't trust the battery take one out of another
one or your cars and do your checking. Some times batteries look good and
test fair when they are actually not good. Even some very new batteries
go bad for no apparent reason.
The starter may be drawing to much amperage. This is common to have it
happen when it is hot because the insulation breaks down over time in the
windings and with heat that gets worse, thus it sort of trys to crank
even though the rest of the system is good. Worn bushings in the starter
also can cause the starter to physically drag. A good Generator / starter
repair shop can fix our Lucas starters and alternators with no problem.
Here in Lodi California the shop uses tractor electrical parts that are
identical off the shelf.
Good Luck
Tom Larsen
74 CF19002U
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