rx04Lexus

I've a 2004 RX330 with about 29k miles (weekend car). Over the past two months, I've experienced on 3 occasions the car would not start. After about 5 - 10 minutes wait, it started fine. A new battery was replaced about 2 years ago. I recently had a local auto store do a battery test and it turned out normal. When an alternator test was done, it read 12.7v. It was suggested that the problem is related to the alternator. Will the alternator need to be replaced? The technician also suggested a possible problem with the wiring from the alternator to the battery. Anyone who has experienced a similar situation? I appreciate the advice in advance.

salimshah

12.7v ouput in your post is the only symptom that points to bad/weak alternator. Every thing else indicates the problem is elsewhere... like waiting 2 minutes etc.

A true test of alternator can be done by removing it from the engine and having it tested in any of the auto-stores on their test bench.

Since in my view the alternator is pretty robust, I tend to look for add on accessory.

Salim

kiwi

sounds like the alternator to me, when you hook up a volt meter with the car running, the charging voltage should be around 14.2v, you are too low, the longer you wait the greater the chances you will need to replace your battery too.

salimshah

You may be right, but alternators can not provide unlimited current. An abnormal load (bad wiring, bad battery or electrical load) can clamp the voltage.

Sine the battery checked out ok, the next step should be ... take the alternator out and have it tested on a bench.

Salim

kiwi

i would be more at to have an alternator handy if i was going to take my old one out, it isnt the easiest job. would hate to see you remove the old one only to have to reinstall it when you do find out its bad. jsut make sure you can return the new one if its not the problem.

after you get the new one in, check the voltage, should read 14.2, and away you go.

of to save some coin, if you have 2 cars, take your old one to a rebuild shop and have them rebuild it,

mandyfig

14.2 to 14.6 should be the charging voltage. If not, the alternator is the source of the issue. The longer you wait, the chances are that the battery will wear out prematurely.

And might get you stranded one day.

Did you get extended warranty? If you did, take it in. They will cover that.

mandyfig

If you are a DIY'er, replacing it should not be a bid deal (I think, have not checked it).

phlfly

What do you mean would not start?
No cranking whatsoever, cranking but very slow, while it's cranking are the cabin lights going deam?
If no cranking it could your starter solenoid is taking too much load.
you can take a measurement on your alternator, with out removing last one. You will need a simple tool, as voltmeter, measure on battery with engine off, then measure on battery with engine on. You should see volt. increase with engine on.

mowmow

rx04Lexus, yea listen to the guys have the alternator checked out and replace asap. I had a boat load of stereo equipment plus a few extra electronics (Tein EDFC, scangaugeII, ) I had Stinger deep cycle battery and it because of the heavy load, it kill my alternator and the battery will drop below 7Volts in 2 days if the car is not started and ran. I constantly had to have a mobile jump start device on hand to be safe.

rx04Lexus

Thanks for all the feedback. Once I've it fixed, I'll post an update.

MMS4MSU

Speaking on mowmow's situation, does lexus/toyota have a bigger & better alternator that can be installed on the rx (400 to be specific)? For all us electronic junkies that pack as many devices in our vehicle as we can. I saw it recommended on a car audio forum one time.

mowmow

I don't know if Toyota/Lexus makes a bigger & better alternator but I do know there is a place up in Central valley that can recoil the factory alternator to make it better or there is always after market alternator also as well as 2nd battery install as an isolator and with all the other electronic hook up to the 2nd battery instead of the primary one.