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Just picked up a new Lexus few weeks back. One night had it playing music with engine off for about an hour and then it would not start. No problem, jump started and I was off. Though I did notice a CEL light up, but it was gone the day after I started my car for the second time after jump start. So we're clear.
Few days back, I take it to AutoZone for a free electrical scan. The machine says the battery has failed. After running the alternator test next, says voltage regulator has failed (granted the diodes are good).
I tested two different locations across multiple days with same results.
Could it be just a new battery that's needed? It still has the Panasonic battery which I believe may be an oem from 2010 (though not sure on that one).
Before I drop in a new battery (and void my return), would love to get some input from y'all. Could it be just a battery issue, or is this indeed a alternator issue also?
It just so happens that I had to replace an alternator on another Lexus (RX350) recently...is this a common theme with Lexus'?
I had no signs/symptoms like yours but I did not wait for those. I had alternator test and reading was not right. Being at 165k miles and reading here with IS alternator issues around 120k, I just had it replaced last year by mechanic. Bought alternator at oreillys and all good. I did not have to worry about alternator issue.
Batteries only last for 18 mo to 2 years here in AZ. Just replaced the battery on my ES330 last month. Sam's club sells Eveready batteries and replace them forever
1st steep is battery. If upon install and running with say nothing but the headlights on, your voltage at the battery better be >13.4 volts. If not, its likely the alternator died also. But you said the diodes tested good so be warned that if the voltage is >14.6v it will kill your battery by over charging it.
Also rev engine to 2500 rpm and monitor voltage. Never should it go over 14.6v.
1st steep is battery. If upon install and running with say nothing but the headlights on, your voltage at the battery better be >13.4 volts. If not, its likely the alternator died also. But you said the diodes tested good so be warned that if the voltage is >14.6v it will kill your battery by over charging it.
Also rev engine to 2500 rpm and monitor voltage. Never should it go over 14.6v.
It is three phase full wave rectifier where the diodes are used and regulator part is usually ASIC chip. Many times alternator can be repaired when taken apart. If diode(s) go bad usually radio will hum specially in AM mode due to increased ripple of the current output. If diode is shorted it is bad. Alternator needs good grounding to operate well. Battery too.
Few here are going to yank an alternator, replace the diodes and/or regulator and hope that fixes it. That said the electronics are the weakest link and when an alternator hits the shelf as a remanufactured component, its lucky to get bearings, a sprague clutch, as many simply replace what has failed and maybe turn the commutator and throw new brushes at it.
What is sad is the 1990's camry's would go 300,000 mi on an OEM alternator... WTF Yoda????
1st steep is battery. If upon install and running with say nothing but the headlights on, your voltage at the battery better be >13.4 volts. If not, its likely the alternator died also. But you said the diodes tested good so be warned that if the voltage is >14.6v it will kill your battery by over charging it.
Also rev engine to 2500 rpm and monitor voltage. Never should it go over 14.6v.
Measured 13.2-3 with lights on...
Originally Posted by 2013FSport
Few here are going to yank an alternator, replace the diodes and/or regulator and hope that fixes it. That said the electronics are the weakest link and when an alternator hits the shelf as a remanufactured component, its lucky to get bearings, a sprague clutch, as many simply replace what has failed and maybe turn the commutator and throw new brushes at it.
What is sad is the 1990's camry's would go 300,000 mi on an OEM alternator... WTF Yoda????
What is your recommended route of going about replacing it then? I only have 53k miles.
04-28-18, 04:48 PM
Battery & Alternator FAILED — ideas?
