Turn a few heavy loads on and you can do a decent test with a voltmeter.
Rear defogger, all the lights, fan motor on high, etc.
You can put a 40 or 50 amp load on the battery.
Much better than just measuring the voltage.
This is incorrect.
The Only way to test a battery is under a load. A multimeter will not and can not load a battery for testing.
Turn a few heavy loads on and you can do a decent test with a voltmeter.
Rear defogger, all the lights, fan motor on high, etc.
You can put a 40 or 50 amp load on the battery.
Much better than just measuring the voltage.
Alright now I'm pissed!!! Car is supposed to be under warranty and they charged us $386.20.
$87.50 tow
$337 for " Performing software update in motor electronic control module" Short test codes 1108,0190,0217, 0551, 1916 etc all relating to throttle actuator blah blah blah.
PS buy American, old preferably.
I'll get tow money back from my insurance but gotta fight merc for the rest. My wife can write the letters I did my part. Paid. Would not have paid had I'd been there.
This is a better test, but nothing like the load a starter motor will put on it, or a load tester.
Ill take solid state sensors and a data log showing me exactly where the problem is over manually checking over miles of vacuum hoses, diaphragms, and sticky worn out crusty mechanical actuators and best guess divide and conquer troubleshooting any day.
Anyone who dislikes current EFI systems because the are too "complex" needs to work on a few cars from the 70s/80s.
If it will crank, then you measure the voltage while cranking it.
If it won't, you gotta use whatever other big load you've got. :biggrin: