Reply With QuoteIf the light doesn't come back on, I would do nothing. If it comes back, take the battery in to Autozone for testing.Originally Posted by Darron65
Weird electrical stuff
Ok, so I'm driving home yesterday, minding my own business, when the charge indicator lights up. I was 10 minutes from home but I pulled over anyway, expecting to find a broken belt which would lead to overheating. No, the belt is still there, the alternator is spinning away. I simply shrug, close the hood, continue home.
After unpacking the car and switching wheels, I connect the battery charger and head inside to get cleaned up. Then I got distracted and didn't look at the car until this morning. The charger was still running around 6 amps after being connected for 11 hours. I disconnect the charger, start the engine and ... no indicator!
What is going on?
If the light doesn't come back on, I would do nothing. If it comes back, take the battery in to Autozone for testing.
I heard of this once before. The guy had been driving all day and stopped a couple of hours before the light came on. After spending several hundred dollars swapping parts, he discovered the culprit was the unlikely combination of a DQ Dude and Blizzard. YMMV
I don't care who you are that's just funny!
Ya got a meter Sparky?? If so try this :
One Very Simple Alternator Test:
1) Start Car and run at a normal idle.
2) Connect a Voltmeter Directly Across the battery Terminals.
3) Turn on Headlights to High Beam.
4) check the battery Voltage.
*** The Battery voltage Should read between about 13.8 to 14.2 volts. (Possibly up to 14.5 Volts.)
5) Increase motor speed to about 1500 RPM. The Alternator should now produce a battery voltage between 14.2 and 14.6
Volts.
*** If it is Lower than 14.2 volts, the Alternator probably has one or more Bad Diodes.
6) Now, Maintain the 1500 RPM and Turn off the Headlights. Run this test for One Full Minute.
"The Battery Voltage should NEVER Exceed about 14.8 Volts".
***If it Does, the Alternators Voltage Regulator is probably Faulty, OVER CHARGING the Battery.
That's good advice, POS and more-or-less what I'd intended to do.
You're just jealous you weren't called "Dude".
Alright so the battery seems okay; it readily takes a charge and holds it overnight (12.6V). Right after startup, I've got 12.1V and the indicator is lit (duh). Thinking I was on a short supply, I didn't test it further with the headlights on. After I got to work I should've checked voltage again but didn't; it had recovered back to 12.6V 3.5 hrs later. Autozone was backed up yesterday but I'll stop again today on the way home and get things tested.
Are Autozone's alternators any better or worse than others? I've been checking the local stores and it seems that none of them has one in stock. Unlike batteries which it appears I don't need.
Last edited by Darron65; 06-12-2007 at 12:02 PM.
Yeah, how hard is it to take a battery to Autozone? Better than trying to guess the problem!!
I can say that now
09 Lexus RX350
.... no Miata
Generally, it's a crap shoot if you get a good one at Autozone/Pepboys/Advance Auto or most of the other discount auto parts places that sell "rebuilt" alternators. You might be better off trying NAPA or going to an alternator repair shop. First tings first, though, use the KISS method of diagnoses. Check the connections for corrosion and tightness first. Make sure the wires on the back of the alternator are not loose. Make sure your battery cables are not swollen at the battery from years of corrosion and the ground terminals are not rusted on the body. Make sure the battery terminals are not corroded to not allow a good connection.
Simple and obvious I know, but sometimes simple keeps it running.
05 MX-5 Mazdaspeed #1024 Titanium Gray Mica
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