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Yesterday after work, when I tried to start my car, it just cranked cranked cranked without turning over. All the lights, radio, etc. worked fine, but the car just wouldn't start. I tried this about 5-6 times and the same result happened. I was able to jump start the car, get to OReilys, and get the battery tested. The battery test said it was a bad battery so I purchased a new one. Today, when I installed the battery, the car started fine (it initially started, then immediately died/stalled but subsequent starts were just fine, about 10 more times).
When I went back to OReilys to turn in my old car battery, I had them test the alternator and it gave an error of "Volt Reg Failed". This is surprising to me as it is only a 2015, with about 50k miles on the odo. Obviously things fail due to wear and tear and some sooner than later but I can't help but wonder is the voltage regulator really done? Mind you, there is no check engine light or battery light this entire time on the dash (nor was it on during my drive home).
So a couple of questions
1 - Is this common for the volt regulator to fail this early? Or could it be something else? Should I test it again just in case of a false positive or is the test pretty accurate? Tested on an Auto Meter advanced electrical system analyzer
2 - If the alternator did indeed fail, can I still drive the car? I think I read the consequences is that it might short or wear out the battery faster? I ask because it is the weekend and some shops might not be open or not have the part on hand.
3 - Do I need to replace the entire alternator?
4 - How much would this run me (parts + labor) or if I were to DIY (parts only)
1 - IMHO no, they usually last at least 100-120k miles
2 - Generally yes, but it depend on the failure:
In case of partial or complete loss of charging the battery has up to 4 hours of reserve
capacity, then the battery needs to be recharged immediately in order to prevent capacity degradation
In case of overcharge / overvoltage it is not recommended to drive the car.
Overvoltage is harmful for the battery (by creating cell grid corrosion which is irreversible, reduces permanently the battery capacity)
and also endangers the onboard electronics.
3 - You can obtain the different parts of the alternator separately (e.g. stator, rotor, bearings, rectifier bridge, regulator, etc.)
I'd recommend a voltage check on the battery terminals at running engine. With all ancillary devices off you should measure 14.1-14.5 Volts.
Turning on headlights, rear window defroster and blower, the voltage should remain at least 14.0 V at idle.
Voltage readings above 15.4V points to the regulator, while voltage below 13.8V can be the result of alternator belt slipping,
failure of the clutch in the alternator's pulley, faulty rectifier bridge, or faulty regulator, or loose contacts (alternator charging terminal or battery terminals),
or maybe a blown fuse related to the charging circuit.
Your motor dying immediately after starting the first time is normal. It does this when the ECU is reset, which happens when the battery is unplugged for around 10-15 mins. See if it causes any more issues from here on out. Hopefully not, if it does, consider having a dealer take a look at it.
I doubt anything is wrong with the Alternator.
If you don't see the battery light on the dash, then keep driving.
Usually the battery and parking brake lights will come on together if there is an Alternator issue.
Sometimes I wonder about these machines locations are using to test batteries/Alternators...and sometimes the issue is the operator, not the machine.
Your motor dying immediately after starting the first time is normal. It does this when the ECU is reset, which happens when the battery is unplugged for around 10-15 mins. See if it causes any more issues from here on out. Hopefully not, if it does, consider having a dealer take a look at it.
i've never heard of that...
anyway.........
OP its hard to say what particular part of your alternator konked out. It's moot anyway as you're best going for a reman which would have serviceable parts replaced. check alternatorpros.com my go to back in the day. they'll have you up and running the next day so long as you can do car work yourself. they give you a box and everything to return your core. replace your belt while you're at it
the alternators on this car seem like a potential failure point since they are so puny compared to the german ones i'm used to which are the size of a human head. these ones are fist-sized. like something you'd expect on a corolla. I'm not sure what they're rated at. When it comes to electronics, bigger is usually better.
OP its hard to say what particular part of your alternator konked out. It's moot anyway as you're best going for a reman which would have serviceable parts replaced. check alternatorpros.com my go to back in the day. they'll have you up and running the next day so long as you can do car work yourself. they give you a box and everything to return your core. replace your belt while you're at it
the alternators on this car seem like a potential failure point since they are so puny compared to the german ones i'm used to which are the size of a human head. these ones are fist-sized. like something you'd expect on a corolla. I'm not sure what they're rated at. When it comes to electronics, bigger is usually better.
Whenever the ECU is reset, whether it be a tune is flashed or reverted, or battery disconnected for a long period of time, the car does this. it’s done it every time i’ve changed tunes...
While we’re at it, the OP might as well go find a totaled 328i at a junkyard, take its alternator, and put it in the IS. I swear, some of the posts i’m seeing, you’re just banking on the 3IS failing to see your german king rise to the top. i don’t know...
back on topic to the op, like sasnuke recommended, just drive it. if a problem occurs, a problem occurs. But it seems your new battery solved the issue. If you really want to be sure, an obd2 scanner could reveal any issue, if one exists im sure.
My alternator on my 2015 rarely gets up past 13.8. Pretty sure these cars are being controlled by the ECU not allowing the voltage to go that high. I suggest you check the voltage at battery with the car started see where you're at. If the new battery is dying it's to the point there's a problem.
Thanks for the response guys! I will continue to carefully monitor the behavior of the car (so far, no issues anywhere). I haven't tested it under a full load yet (AC, seat warmers, etc.). I will check the multi-meter to see what its putting out this week as well. I also called my independent Lexus-certified mechanic and he mentions the same thing - don't worry about it, especially if using the shops reader and given the relatively new car + mileage.
I've attached the error message that the reader put out for the curious
Thanks for the response guys! I will continue to carefully monitor the behavior of the car (so far, no issues anywhere). I haven't tested it under a full load yet (AC, seat warmers, etc.). I will check the multi-meter to see what its putting out this week as well. I also called my independent Lexus-certified mechanic and he mentions the same thing - don't worry about it, especially if using the shops reader and given the relatively new car + mileage.
I've attached the error message that the reader put out for the curious
Hello there, i'm having the same situation as you.
The engine start voltage is peaking at 12.9v - 13.2 ish. After driving for 30+ mins the battery voltage is between 12.45V-12.9V. Would this indicate that my alternator is going bad?
What did you end up doing and did you change the entire alternator part or just the voltage regular part in the alternator? Thank you.
10-11-19, 09:03 PM
Voltage Regulator failure?
