nlowin

Help, My 1997 ES300 is eating alternators like a stoner on doritos.
I'm going on my fifth alternator in 6 months.
The first one was the stock alternator.
It last 165000 miles and almost 20 years.
I installed the second one myself and didnt think much about the failure.
I figured that was normal for the mileage.
The third was done by a mechanic that swore he knows the ES300 backwards n forwards.
The part was warrantied but the labor cost.
He couldn't find anything else wrong.
It lasted a month.
The fourth alternator was installed by another mechanic.
He swore that the previous alternators were just cheap Oreilly parts.
He put a nipondenso alternator in.
He looked for other issues but didn't find any.
The fourth alternator is now failing slowly.
I see it failing as I have a voltage meter in the ciggie lighter.
It goes up to 13.7 on startup n down as low as 11.7 with lights and A/C (in FL).

That seems to be the issue,
Lights and A/C.
If I turn them off the Voltage goes back up.
And more the A/C than the lights.

So The A/C is belt driven.
Why would using the A/C overtax my alternator ?
Help ?

This was the most dependable I car I'd ever owned and I've owned a lot of cars.
Other than this the car runs great.
170k miles and doesn't use a drop of oil.

Please help me make my car dependable again.

Thanks

AnonymousES300Owner

I'm having the same problem... Did you ever get this fixed?

When I start the car, I'm 14.5v's at the battery. I have no check engine codes popping up, although my check engine light is burned out, but had it scanned multiple times.
When I turn the AC on it immediately starts going down to around 12 incrementally, or if I just leave the car on till it idles or warms up (waiting 5 minutes) it will also go to low 12 volt range.

*I've added Big 3 wiring just incase I had any connection problems. Tested with voltmeter, everything was fine anyways.
*Cleaned the throttle body and the IAC valve
*Put in new fuses (not the relays), although the old ones weren't bad anyway.
*Tightened the screw at the throttle body to increase my idle RPM, but that just made things more erratic, so adjusted it back down.
*Tested the resistance on the front 02 sensor, and it did only read 1.4 ohms of resistance, and I think it's supposed to be above 2..

I'm on my fourth alternator, this time I'm upgrading to the 130A highlander alternator hoping it will make up the difference.. I'm concerned that this wont fix it, and I waisted $150 for a diagnosis that told me it was my alternator even though I've had three in a few months.

I had a couple people suggest it might be the compressor because the voltage drops when turning on the AC, but I find that highly improbable. A/C works great, unplugged the fans to see if that was the source of the voltage drop, and I have no leaks.

My next guesses are that as mentioned before it might be an 02 sensor, a fuel injector/pump/rod (w/e), or maybe even my IAC sensor. These are the last possible conclusions I could come up with.

LeX2K

Let me guess you've been buying alternators at the local parts store.

AnonymousES300Owner

Amazon... I did check to see quality ratings before buying them, the DBElectrical alternator apparently rated better than the Delco, so I went with that.. The new one I ordered is a-premium brand.

I've used Amazon alternators before in other cars and didn't have a problem.. I was opposed to getting the OEM alternator, but the mechanic near me said it might be a better choice to increase the amperage on the alternator and just go with a highlander alternator.

AnonymousES300Owner

*Not opposed to getting the OEM alternator

LeX2K

Direct bolt-in upgrade.
https://www.rockauto.com/en/moreinfo...t=2412&jsn=456

discount code: 244463805126776304