Bad alternator?
 

Okay, so I have been having some electrical problems with my 8. they are very peculiar, so here we go:

first off, I notice that my low battery indicator is on this morning. No problem, I thought, since I hadn't driven my 8 in a few days. so, as I fire up my car to drive home that night after class, i see the same low battery indicator, no big deal. I figured as I drove, it would charge up in no time.

I was dead wrong. As I drove, the power seemed to get lower and lower, and it got to the point (it was nighttime) where my lights turned off, my powersteering went, the dashboard, everything, and was barely idling.

Obviously, I am in a panic, so I pulled over, and called my friend to let him what was going on. I wait about 10 minutes, it seems like my battery hits rock bottom, then, everything magically turns back on like nothing happened, even the low battery indicator is gone... very strange.

This happened three times consistently, just like the above incident.

So I take my 8 to autozone, and they say my battery and alternator is FINE, and I take it to "Gem Mazda" and THEY say I need a new alternator for $750 +$90 diagnostic- a totally bullshit price, considering a brand fucking new alternator only costs $420.

They also said I might need a new PCM, which I call bullshit on, that just doesn't make any sense... The asshole on the phone didn't even give the correct description of what a pcm IS....

Last thing, does anyone know how to change an alternator if this happens to be the case? I'm not paying those asswipes $300+ for something I could possibly do myself, I am a broke college kid that could make better use of the money.

Please, any help would be very much appreciated! Rotarygod, I know you're lurking out there somewhere! :D

The alternator is a simple change I expect. As long as the battery, battery box, and intake are removed to make room, should be very simple process. I was helping with the water pump right below it, and didn't see anything with the alternator that would have made it difficult.

That being said, if would expect that it is -not- your alternator, but rather a connection, frayed wiring, corroded contact, or something like that. If your alternator itself was bad, then it wouldn't suddenly come back to life several times, and autozone probably would have found something wrong with it. The sometimes issues, sometimes not is generally associated with corroded battery terminals, but generally an instant on-off type issue, not a fading on and off. The vibration from driving is wiggling something around most likely, causing intermittent connection.

So take that corroded concept and find somewhere else it could be causing the issue.

I would start with your battery and follow the connections to your alternator. Disconnect, inspect, clean, and reconnect as you go. Hopefully something will jump out at you as clearly wrong.

Seems strange that the alternator could "heal" itself; check and clean your battery connections and see if you can duplicate the problem.

good way to check ur alternator(if u dont have a voltmeter)....is get a long screwdriver or something metal and hold it near the pulley(while running)..the alt pulley should be magnetized when operating properly and pull the screw driver

NOTE: I know this is not the technical way to test it but for a "broke college kid" that may not have a voltmeter a good way to make sure it's magnetized which for the most part means it's still working(yes it could be magnetized and not work but usually not)

***I am not responsible for you being dumb and getting the steel object caught in the pulley/belt and stabbing yourself

Sounds like the problems I had and my alternator ended up over charging and ruining my ABS unit. Take it off and take it to an alternator shop (not Autozone) and get it tested, they won't charge you. If its bad get a used one on ebay or get it rebuilt. But keep in mind I had mine rebuilt twice because it failed again. Something in the rebuild process does not get addressed. After the second time I just got a slightly used one on ebay from a wrecked 8.


Removing and reinstalling is easy just remove the bracket that holds it.

I once had symptoms in a car similar and it was as suggested above. I wonder if you simply need to clean your battery cables/terminals. Are they significantly corroded? Are the cables lose? Use a proper brush and clean the terminals and the cable connectors. It's essentially free to check/fix. Alternatively there's a little electrical peice attached to the alternator that can fail and/or cause intermittant behaviour. I'm having trouble thinking of the word... Anyone :)

I'm sure the FSM has an alternator diagnostic procedure...

FYI #1: You should be able to get a rebuilt alternator for significantly less than listed. While I've never priced a RX-8 alternator, a typical rebuilt price would be ~$100-150.
FYI #2: Decent multimeters can be had for <$20 and everyone needs one.

I paid $100.00 for the rebuild and it was rebuilt the second time under warranty. I actually have my old "bad" rebuilt alternator if any one needs it for a rebuild or core. I felt bad for the guys that rebuilt it because they could not figure out why it kept failing but I got my $100.00 worth so I wasn't mad.

Which Autozone? If it was were I think it was, those guys are pretty good at that particular store.
I'm going with everyone else in that I think you have a bad or corroded connection. Do you have a meter? If not and you're still in my area, then pop over and I can at least check it out for you. If you need to change the alternator, I could probably find time to help you out there too! It's not that bad.

hey mazsurfer, whatsup? its been a while, good to see you still lurking around rx8club :D- i used to live very close to you, but now i moved to tallahassee for school...

wow, thats for the insights, everyone, they are much appreciated!

but um, not that i think about it, the terminals are slightly oxidized, but only a little.

I should get a multimeter very soon though, and consider my options, cant right now though, got a huge chemistry test to study for the time being...

Clean all the connections really good and then apply some battery terminal grease. If nothing else, use a little petroleum jelly after reattaching.
When you do get a meter, with the car running you should get just about 14.2v at the battery and while not 100% final, that will tell you if the alternator is most likely okay.
With all that you described, I still think it's just lousy connections.

FSU huh? Had one of my daughters go there.

Can't vouche for any Autozone up there.........good luck!

you HAD a daughter go here? how old ARE you? lol thanks though, just did my chem test, going out to get that meter, and some cleaner for the terminals