I have a 2001 Lexus LX470 that won’t charge the battery. The alternator, the belt tensioner and the serpentine belt were replaced today. It still won’t charge and I am lost at what to look at next. The two frame grounds near the battery have been checked, cleaned and tightened. All of the fuses are good. The junction/assembly box off of the positive battery cable was disassembled and the connections cleaned. (I may try replacing this so if anyone knows a way to either better wire it or a part number that would be appreciated.) But all connections and grounds everywhere seem to be in good shape. When the voltmeter is on the hot post of the alternator and grounded, it still reads low. I’m lost and don’t know where to look next. Thanks I’m advance.
Help: Battery Charging (2 Viewers)
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If a reman was installed it is very possible to get a bad unit out of the box.
The reman market has taken a beating over the last 3 years with poor QC
The reman market has taken a beating over the last 3 years with poor QC
It's a fairly simple charging circuit and you mentioned you already checked the alt fuse/relay assembly.
Does the batt light work on the instrument cluster?
Be helpful if you list Part number of alternator, where purchased and which battery you have.
Also what symptom, that lead you to look at alternator. Slow cranking, no crank diming dash lights, no crank no dimming, cranking fast no start.
You tested voltage at alternator. I'll first Assume, by the book (FSM) and voltage below minimum (you said: low). Then, Alternator is bad. So replace it with Toyota Denso.
It's very rare for a Toyota Denso remanufacture alternator, to be bad out of the box or even go bad in the short term. Toyota has a list of parts, that must be replaced at a minimum. Any other reman even non Toyota Denso. What parts replaced, is up to rebuilder.
A few possibilities, why alternator going bad:
- Aftermarket reman.
- #1 skid missing.
- Deep water crossing.
If you indeed have a bad Alternator, not delivery a full change. You battery would also be bad.
It's also possible, a mistake made in testing of/at alternator and issue is battery. You mention 2 alternators in 3 years:
18 months is about the time it takes to damage a battery, Sulfate. When not keep fully changed and cycled. To the point it will not except enough of a charge, for good cranking;
- Not a daily driver and not keep on a good desulfating battery charger.
- Oxidation or even some products, like a can of CRC battery red spray or even some greases on battery post will inhibited connection. We then get less AMP through battery clamp into the posts. Test from +clamp to -clamp, then +post to -post, then +post to -clamp, then +clamp to a body ground. Volts should read the same, at all points.
Note:
Best battery in Colorado, is the Group 27F for our winters. 24F just don't have the cold cranking we need.
Parasitic draw. OM states; do not leave headlights SW on AUTO, during prolonged parking. Increase the parasitic draw.
Rear DVD players are known for parasitic draw.
ANY aftermarket wiring & toys, need close look.
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Do you have your old OEM alternator? if you do replace the brush kit. If not, try locating a Denso reman.
