Automotive help.
 

Alternator died last night, battery light came on. Replaced with a used one I had for a spare. Ran fine all day.

Suddenly it doesn't seem to be charging again. Lights went dim, overdrive wouldn't work, radio was flicking on and off. But the oddball part is the charge light didn't come on. It's weird. Made it home, but now the battery is dead of course.

Will an alternator die without showing a dash light?

I don't even have a multimeter to my name at the moment or a charger.

What model of vehicle are we talking about?

Older Kia rio.

I have zero experience with that particular vehicle, but it seems unlikely that you would loose two alternators in a day.

Was this used alternator known to be good?

Did you recheck your wiring connections, belt tension etc after your install?

With the vehicle running if you remove a battery clamp briefly does the engine die?

Your battery could be the culprit as well, if it has a cell shorted it out it could be killing off your alternator.

Did you have the alternator you removed tested at a part store? Crappy Tire and the sort will generally do this for free.

Yes, A bad Battery will pull down your system, make your engine run rough. Very hard on the charging system.
Good to replace battery when you suspect it acting up, slow cranking when cold. Also if you accidentally flatten it out if more than 5 years old and doesn't crank like before. Alternators are sometimes pricier than Batteries.

It's a used alternator off my original Rio, probably been kicking around the trunk for the last 8 years so it wouldn't surprise me if it's corroded or what not. I should have gotten a new one as a spare but oh well, live and learn.

Yes, when I removed the negative, the car died - so I suspect she's not charging, alternator could be corroded and shorted internally.
.
I've just never seen an alternator die without indicator light.

The battery is only 6 months old, and I tend not to cheap out on parts. Drove for a good 20 minutes on battery only tonite, engine ran fine. Figure one good charge and it'll be back to life.


Another $250 for an alternator.

Certainly don't know Kia's but

Some cars use the Bat light circuit as field excitation also.
Would explain the lack of warning lite.

Ck for a burnt 5a fuse (and a grnded field in 2nd alternator)




edit: Saw the post re shorted battery cell suspected...

Alternators are usually self-limiting in current output.

Do you remember the kits that fed full field volts
and you could weld with your alternator

Never thought about fuses, will check tomorrow. Having a couple of shots of rye at the moment, the car can wait.

Voltage regulator?

I'll check that tomorrow as well...



Funny tho, check engine light came on as well. Plug in the reader, but no codes.

Again, I know nothing about Kia's but likely the voltage regulator is built into your alternator, most are.

If you can get charged or get a ride, take your alternator that you already have off to a starter/alternator shop, they can test it for you and likely rebuild it for much less than you will pay for an exchange unit from a major parts house.

If you have some skills, you can generally rebuild an alternator yourself for very cheap. Most aprt places sell kits for them. They are pretty simple components.

Skills aren't a problem, my cars have only see a garage twice for major warranty stuff, otherwise I do it myself. Rebuilt many alternators over the years, can't find one for the Rio unfortunately. Stuck buying a reman or new. and Canadian Tire is the only one that has one in stock. I'll be pulling it in the morning, get it tested and hopefully it fails, don't want to be chasing electrical issues.

Haha, yes I do remember those. I think they are still being sold on ebay and the like actually.

As for self limiting, yes self limiting when they work right! haha.

But back to the OP's question, there may be a heavy fuse either on the alternator itself or in the wiring nearby, I would almost bet on it. If you can find that fuse check it, it may have blown when the other alternator died.

Do not do this. If you disconnect your battery while running you stand a very real chance of blowing out your voltage regulator.

Last winter I drove out to almost Fox Creek sledding in the morning. Lights, heater etc on. No warning lights. Parked and sledded all day. Get back, hit the car starter while we loaded, lights dimmed, then truck died. Boosting kept it running. No lights in dash until it died. It was the alternator. Left truck over night, came back in the am with a brand new battery and got the truck home. When that battery died in the city, we knew it was the alternator. No dash warning lights either.

Can happen.


I would say the used alternator is no good or almost done.

check voltage on the battery terminals when the engine is running should be around 14 volts otherwise the car will only run until the battery is dead.

Yup, make sure your field wire has voltage, or you may buy another alternator for nothing

as they said above , a faulty battery will give you problems , get a new one from costco .

Expensive day, new alternator, battery charger and meter plus a round trip with Uber.

I'm sure the alternator is bad. Was thinking about it last night, it's been kicking around the trunk for the last 8 years. Likely suffering corrosion.

Often when either an alternator or battery craps out, it will severely stress the other component enough to eventually kill it too, even if it started out in good health.

The only reason I didn't replace my alternator when my factory battery died (7 years in) is that I ordered my truck with a trailer package and heavy-duty everything. So I figured it could stand a bit of excessive charging load for awhile. Otherwise I'd swap out both as a pair and save the price of an 800 dollar tow off the top of a mountain somewhere.

Life gets interesting enough without playing whack-a-mole with electrical parts.

Main power fuse is blown, 80 amps. When I changed the alternator the other night, I think I might have grounded the positive lead from the alternator to the body of it.

Well, maybe your 8 year old alt. is still good as a spare :)

Hope so, i'll get it tested this time to make sure.

If you are ever in Calgary leave the old alternator with Mac's Auto Electric in the NE.
Have Eddie rebuild it for a later date.

The Auto Electric Whisperer

Well, changed the fuse and all is good. The fuse block melted into plastic fuse box, had to break it up to get it out. Dealer didn't have the exact one, had to bend and cut the one they had to make it fit but...

When the alternator died the first time, it gave an indicator light. When the main fuse (80 amp in my case) is blown, no indication and no charging.

It will be SO cool when they finally get that ridiculous 12V system replaced with some sort of 208V 3-phase bus. And build the starter and alternator into one part.

And build an Inverter and rectifier as an integral part onto every battery, like coil-overs sitting on top of spark plugs now.