So, on my 09 ISF w/20k mi I replaced the battery on 10/14. Now, about every 2 weeks the batt goes dead. I had it tested-it's ok. I also had the system load tested at Auto zone. It showed the alternator not fully charging. Hard to believe the alt has failed with such low mileage. Any ideas?

 

Its probably the alternator. Some electrical parts will start to fail if left unintended for. Yours is super low miles for a 2009. Replace thr alternator and see if that resolves your issue.

 

Have you check the alternator belt? Maybe its worn out thats why its not functioning properly

 

800-900 for just the alternator is crazy. Can they be rebuilt?


That's something I will look into before pulling the trigger on a replacement.

Thanks for the responses!

 

$800 to $900 is a joke. Shop around and get a rebuilt one. Rock Auto has them for $120.00 plus core.

I would take mine to a commercial truck alternator shop and have it rebuilt. Then keep it as a spare. Yours probably has some minor issue anyway. Much easier to have one ready to go when doing the R&R. I can't remember but I thing replacing the alternator is not simple on an F.

Be sure that is your issue first.

 

At idle the the battery measures 14.18V. Doesn't look good...

 

And a bad joke at that. Thanks for the advice.

 

There isn't an alternator belt. There is one belt, and it drives everything.

The only thing that makes sense is to first check and see if you still have warranty coverage - your mileage is super low, so it's just a matter of "in service" date to determine if warranty covers this.

If it is not covered by warranty, remove the alternator and have it tested independently. It sounds like you lost one phase of the output. Repair the alternator will likely be not cost effective because the integrate the diode bridge/regulator into the coil assembly, and Lexus wants crazy money for the coil assembly and not much more for the whole unit. So, if you don't want to spend a fortune, hit up one of the aftermarket sources for a rebuilt unit.

If you really are someone who wants to fix things, it's possible to source diode bridges and regulators from online resources, but you will need to know precisely which parts you need by opening the unit and getting the Denso part number off the individual component.

The wife's tC did a similar thing recently, and it did not make sense to repair the unit with Toyota parts. I bought a rebuilt unit at Autozone and replaced the battery at the same time. Both were bad because the alternator failed internally. She had 206k miles on the original unit.

 

Thanks Lobux, best info yet. I ordered a rebuilt from Rock auto...

 

Yup, just did the same on my tC with 150K on

 

Did you end up doing the job yourself or did you have a shop do it? If so, how much did your shop charge for a job like this?

 

I got estimates in the $300+ range, not too bad. I did attempt the job myself. I ran into a problem when trying to remove two studs that have torx heads.I was afraid of breaking/damaging them, so I haven't changed the alt yet. I'm waiting for my back to get better so I can tackle this.

 

Sorry for bringing this thread back to life but i have a 2008 w/ 130k miles and autozone testing showed that the alternator is not charging up the battery... so have been having to jump start it with my portable battery...

Planning on tackling this myself... Service manual calls to have to remove the V-Ribbed belt... What 5mm diameter "bar" did you use to align the holes? A screwdriver work? And when putting the belt back on, how do you know if the belt is not too loose or too tight?

Also, will a deep E8 torx socket needed or just a short regular E8 socket work?

TIA

 

It's been a while, but I don't recall Having to align any holes. IIRC, I used a socket & breaker bar to loosen the the tension on the tensioner. The clearance is tight removing the torx bolts holding the the alt. A std length socket will work, but I would recommend a torx box wrench.

Best of luck-

 

So i did this last night myself... so tight of space to work with though.. i just bought a reman from advance auto since a location had it in stock, didn't have patience to wait for it to ship since it's my daily car...
TIPS:

1) regular E8 torx socket works fine - i accidentally bought a longer deeper socket and there wasn't enough clearance with that - easier to work from the top of the engine bay for those two screws and bolts
2) i didn't need to remove the coolant reservoir
3) There's an alignment hole on the bottom of the tensioner and an indention to where you can place a rod in to make it easier to re-route the v-ribbed belt back onto it as it will hold the tensioner in place so that you can have 2 hands to work with, rather than hold a wrench to it while you try to re-route the belt
4) the ring connector that connects to the alternator with a nut can be a little tricky - there are 2 "teeths" that slide into the groove on the alternator, since it's mounted to the top, it'll be all done by feel since there is no space to look at it directly - make sure the teeth goes in the groove and it sits flush - you think you have it on correctly but you have to spin it a little to make it sit flush - tightening the bolt is a little tuff too so a stubby wrench would work - i didn't have one on hand but the small wrench (14mm) that comes with the car's tool kit worked OK but i had to do some hand cramping maneuvering - I have aftermarket headers so i assume there is more space to work with as there are no heat shields and the top of the alternator is right next to the headers and engine mount...
5) the harness connector next to the ring connector is held on by a push tab - the tab is on the side facing the rear of the car - push and you will hear a click and it'll release - i tried to do it without loosening the bolts on the actual alternator but that was difficult since it's so a tight space - trick that worked for me was to carefully support the generator with all the bolts undone so that it slides down like you are about to remove the whole unit from the car and now you have more room to release that tab...
6) there's a small E6 Torx screw that needed to be removed to be transferred to the reman unit i had
7) removing the sway bar - there is a height sensor that needs to be disconnected on the driver's side - i had to use a bent/angled nose plier to hold the nut on the underside while loosening the top nut off of the bolt

Since you should remove the sway bar, i went ahead and replaced it w/ new bushings - brand is Moog from the auto parts store - i think it quieted down a knock that i would hear over bumps

It took me about 3-4 hrs but that's with jacking the car up on stands and removing and putting the engine under cover back on without a power tool

Any other questions i would happily answer