bmore430

Wife called me and said she was stranded because Lexus wouldnt start. Got a jump start and car made it 10 miles home before quitting in the driveway dead as a doornail.

Turns out the alternator was not charging and discharged the 5 year old Optima yellow top to empty. These cars are smart in that they shut off the radio, hvac and lights to conserve charge when issue like this happens to limp home.

Ordered Denso replacement from Amazon for 250.00 and got a new Optima Red Top to do the job at home.

The whole thing can be done with a 10mm, 12mm and 14mm socket set. Disconnect battery, remove drive belt, jack car up and remove undertray. Once you are underneath you have access to 3 nuts/bolts that hold it on and unplug the harness on the rear.

My car is a 2005 with 116k miles. We got lucky and didnt have to get towed but for other members who have 100k or more miles on the original one, I would replace it before it dies and leaves you stranded somewhere. Its a good piece of mind job that can be completed in less than 2 hours.

2KHarrier

Thanks for the great reminder on preventative maintenance. Absolutely could be well worth replacing before failure especially if you've got some miles on the car.

BMW7_LS430

There is another thread where people are posting who are on the original alternator. OP there did not want failures to be posted (Here is the link). let's use this thread to post if your alternator failed and at what miles?

2004 LS430 - Alternator failed at 90K miles - Replaced with Autozone version

Fortunately my failure was discovered by my family with car in the garage during my business trip. No towing was required. I needed to get it running quickly. I just got one from Autozone and it has been fine now at 113K miles.

I do not believe failure is common therefore replacing it as maintenance item may not be a good idea.

Bocatrip

Good point. With all the LS430s out there, alternator replacement has still been quite rare. Yes it happens, but it is not common. I agree that replacing it as a maintenance item is not really necessary. There is a thread on all the owners driving around with original alternators. The OEM Denso unit is quite robust.

Gronemus

Speaking of PM, I though you were supposed to be changing your timing belt today???? Get back out to the garage!!!

bradland

Amazon price - $243.32
Rockauto price - $125.79

Maybe Amazon Prime had it on your doorstep the next morning, which is worth something, but is it worth the price of (almost) 2 alternators....?

Gronemus

There might be more to the story. Maybe that $250 includes the core charge which is an additional $68 on the Rockauto price. Amazon does post different prices on the same item to different people based on your web viewing habits...

2KHarrier

I'm at work today... Have to keep 'em flying...!

I'm on vacation starting Tuesday, so I'll be starting it Thursday morning and should finish late afternoon.. I'll be taking photos..

bradland

Not disagreeing with you but Rockauto does an excellent job of facilitating the core return so the charge is a non issue. I recently bought a Denso alternator for my 400 and Rockauto provided a return label at their corporate discounted rate which was subtracted from the core charge. Very easy and fast I think the price to send it back was about $10.

Johnhav430

sweet...this failed on my wife's SUV last Sat. Rapidly....howl/whine started Friday, by Sat. evening, car went into battery saver mode. We had the extended warranty but I looked up the job and it's about $1,000, for a GM vehicle. Look at the procedure and yes, a/c lines, p/s lines, etc. Nice to know the LS is easy. GM part is also made by Denso, and lists for $678...

p.s. why her car needs a voltmeter is beyond me, but high voltage (and it is intelligent where it drops it when not needed) seems to indicate trouble. Battery going bad, volts high. Alt fail, batt is good, and volts high. Now it seems to be 14.25 most of the time, and even drops down to 13.x implying battery is full. When bad 16v+...

bmore430

Amazon had it to my door in 2 days so minimal downtime was the goal as car is daily driver and wife cant drive stick so cant drive the z06 in garage. As soon as she got car home i placed the order and admit i didnt shop around. 125.79 seems quite low for a Denso though, almost too good id be skeptical.

I just sold a 2006 LS430 at my job with 216k and owner said he had his alternator fail at 180k and leave him on side of the road.