Will lack of use ruin an alternator?

[Brandon73fjord]

The alternator on my 6 series was replaced last year. It is started twice a month and driven around the block just to keep the fluids circulated. I know this is an 02' board, but the roadfly guys think they are too good to answer questions like this. Do you think the regulator is out? thanks

[MatthewCervi]

Shouldn't bother the alternator, but I wouldn't count on the battery lasting too long unless you run the car long enough each time to charge up the battery.

[Brandon73fjord]

When not in use the battery is left on my deltran charger.

[jmon0261]

Great question Brandon that I will also ask.

I got a new alternator last year and have a draw from the alarm system.

At times I did not drive my car enough and drained the battery,

Yes I should have disconnected the battery.

Now that my car is back in action and being driven regularly again, the alternator light has been coming on intermittently. Usually faintly and rarely constantly on bright. Car starts up fine but the idiot light has me scared, I am wondering if it is on its way out and how much can I trust it at this point. I also had the alternator belt tightened which does help.

But ...

Do you guys think that it will test faulty at the parts store and i will be able to get a replacement on warenty or did I wear it out by charging a low battery too many times?

The previous owner had a big stereo in it so it has a 318 alternator in it.

Thanks

[BillWilliams]

Dead or dying batteries should be charged with a battery charger, not the alternator.

[Guest Anonymous]

Neither one of the questions posted strikes me as being a peculiarly BMW issue.

The alternator is one part that in my opinion could sit indefinitely. The wear parts are bearings that are permanently lubricated and brushes. Unless you are parking the car in a corrosive environment, the brushes and commutator should be self cleaning and fine. On your newer alternator, the voltage regulator is a sealed transistorized unit that screws into the back of that alternator. It is integrated with the brush assembly. Why it should fail due to non-use also escapes me.

Worrying about how an alternator will test at the parts store and whether the parts store will honor its warranty makes no sense. If we have a show of hands favoring one opinion, how is that going to impact the store's decision and testing? If your battery is shot or won't hold much of a charge it will make your alternator work hard.

I don't know how that invalidates a warranty unless I knew the specifics of the warranty. The alternator is supposed to maintain the charge on a fully functioning battery. It is not designed to fix a battery that will no longer hold a charge. If the alternator is forced to produce a charge for a long enough time it may lead to premature failure. Is that abuse or normal wear and service? You should be able to make this call yourself.

If the warranty is for a year and the alternator no longer charges - even with a bad battery, a year is a year and I would tip the scale in favor of honoring the warranty. Batteries go bad but I have never heard of an argument for dishonoring an alternator or battery warranty that the vehicle wasn't driven enough during the warranty period.

[c.d.iesel]

...no, - alternator sitting will not cause badness

poorly rebuilt alternator will generally (depending on who rebuilt it and if they replaced the diode board?)will die unexpecticly

poor wiriing connections will be bad - look at the back of the alternator and ar your battery terminals, and any small wires coming from the positive post

GOT any 'extra' toys wired in to the car that BMW did not install when the car was built originally? because they usually are the cause before anyting else(constant draw)

the poor voltage regulator(external) is always the last guy on the blame list,

he's just that good. UNLESS you have 'later' charging system

with an alternator with built in regulator, then the usual cause is worn out brushes - easy enough to look at the brushes by removing just

2 screws. If it so -- and a ORIGINAL alternator to the car,

replace (the built-in regulator) as normal 75,000 mile maintenance.(because of the worn brushes)

so which alternator and regulator system does yer car have?

this poor guy is almost NEVER the cause for problem-=>