lexus-is2

I've read a lot of stories of peoples alternators packing up. Just wondering what the symptoms of a alternator that is failing? My 2006 Is250 RWD has 189k miles that converts to about just oer 300k km. I'm still on my original alternator and not having any issues but seeing as so many people have had alternators replaced just wondering if I should replace as a precaution or wait until problems arise. What kind of symptoms will it give?

gone2morro

My 2008 had about the same mileage as yours when my alternator went out. Basically EVERY light on the dash will light up and/or flash. The power steering will be almost non-existent, the a/c will stop working and the engine will finally cut off and not start. Basically because the battery will be depleted from no alt. to charge it. I replaced mine myself. It's a big job....time consuming, but just watch videos on youtube and you can save yourself a bunch of money!

Bichon

First symptom is typically that the charging system warning light (looks like a battery symbol) on the dashboard illuminates. If you ignore it, your battery will gradually discharge and you'll start to see lots of strange electrical glitches, possible check engine light (random codes from modules that aren't receiving good power) and eventually loss of power steering and inability to accelerate (due to drive-by-wire throttle).

lexus-is2

So is it worth changing out or should I wait for it to go? I'm assuming while driving if it fails it wont generate power to be able to supply everything? Is there ways you can test it to see if it's still ok?

gone2morro

It can be checked while still on car. Are you in Great Britain? If so, not sure where over there, but in the US any parts store can check it.....Autozone, Advance Auto, etc.

lexus-is2

Yes I am. I have access to a multimeter, i know some people say to measure the voltage on the battery with car off it should read 12 point something and with car on it should read 14 point something but is this enough to tell you if alternator is ok or not. Do the parts store have better ways to test alternators?

gone2morro

A multi meter will help and those numbers are accurate, but it's harder to tell if it's the alternator or battery unless you have one of the devices the auto parts stores use.

lexus-is2

My battery is about 4 or 5 months old as I replaced it recently because the previous one was too old and died on me and wasnt holding charge. New battery has been fine since. So will this multimeter test with those numbers be a good way to test the alternator considering battery is new? what kind of reading will a dying alternator give? does it slowly start producing less voltage? so to do the 14.4v test do I need to turn off things like AC and lights when car is on so that its not draining and reducing the voltage reading

MikeFig82

iTrader: (13)

On cold start it will read upper mid 14+ V. Once it reaches operating temp. It will hoover at around 13.2 to 13.8. Now with load it will read different across the board.

gone2morro

Since your battery is new, I think this will be a good way to test the alternator....maybe some of the other people will chime in since I'm not 100% certain, but I know that when my alternator went out, I had a battery less than a yr old and it killed my battery. Luckily the battery was still in warranty and I got a full replacement.
Just a note: I had no prior warning on my alternator and I was 60 miles from home when it went out. I had to have it towed home.

lexus-is2

I test this just across the + and - terminals of the battery itself right? what kind of measurements will a failing alternator give?

Mine has 5 year warranty, so the battery is safe in that scenario.

Gville350

iTrader: (10)

I my case, the ALT failed on ONE drive...out over time. During a rather rainy day, I noticed my windshield wipers not swiping across the windshield as quickly as normal. Then at a stop light, I got the battery symbol came up on the cluster. A couple lights later (1 mile from my house), the power steering went out, along with the audio and NAV screen. 10 seconds down the road leading to my house, the car shut off while at 45mph. Parked in the nearest parking spot and called in a tow to get me home. While parked, I noticed an electrical burning smell. Opened the hood and there was a bit of smoke coming from the ALT area.

*Sidenote, when in a situation when you see the ALT failing while driving, do not use your turn signals or E-flashers. They draw a rather large amount of power and if I had not used them heading home that day, I just might have made it the rest of that mile home.

MikeFig82

iTrader: (13)

Mine just went out last week while driving. For 3 days it had a burning plastic smell. It got worse on the third. I checked voltage with scan tool it was 11V with load. I was able to get home. Went to Oriley's and purchased the ultima brand, and replaced it in a few hours. It never gave me a warning light it probably would have if left longer.

In all if you smell what seems like burning plastic that's a sure sign it's about to take a nose dive.

lexus-is2

Good to know were you getting that smell coming into the cabin? i'll measure the voltage and see and keep an eye on it.

MikeFig82

iTrader: (13)

It was a little if I ran in fresh air mode. Then it was really bad once car was parked. The smell was really terrible I could smell it from a few feet away. I new it was the alternator. I was just in denial thinking about doing the work out in the cold.

Another note the car was very hesitant no dim lights, or anything just hesitant.