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Hi all, I have a 90 with 165k miles. I have the battery, low oil, brake, coolant, and replace light bulb light on. Started last week under heavy acceleration when I passed a semi truck. They flashed on and then went off. Then happened again a few days later under same circumstances. They flashed on and then off 30 secs later. I did have a rear tail light out, so I replaced it today along with changing the oil. I take it for a spin and gun it onto the freeway and the lights came back on but this time they stayed on.
I tried using a jumper wire to search for codes stored in the computer but only result I have is the check engine light and O/D light flashing constantly. I searched many threads all day and have concluded the flashing lights mean there were no codes given. Is this correct?
Battery is a little over 12v off and 14.4 when engine is on. Power steering pump and hoses replaced 40k miles ago and looking dry underneath. Nothing dripping on alternator. Alternator looks new but can't see a part number. It runs fine and normal. I do remember upon start up in the morning that it had a drain on power for 5 secs (like a/c had just been turned on draining sound). Any help or advice would be appreciated!
Having all those lights come on at the same time is a clear indicator of a problem with the charging system. Most likely the alternator. If it's an intermittent problem, the lights will all come and all go along with the problem. 14.4V is perfect, but when you're getting that, are the lights all gone?
You might try putting a voltage gauge in the cigarette lighter outlet, so you get actual voltage readings while driving to see if the voltage comes and goes when the dash lights go and come.
Brushes wearing out is something that just happens with alternators. No way to avoid it. Having PS fluid dripping in there seems to make the problem worse.
Easy to remove the alternator
- jack car up or drive onto ramps, remove engine undercover for access
- remove enough of the air intake stuff to get an easy look at the drive belt
- remove drive belt, at least from the alternator pulley. Can leave the rest of it in place for convenience.- remove 14mm nut and 14mm bolt holding the alternator in place. I think they are roughly at about 1 o'clock and 5 o'clock.
- plastic clip electrical connector can unsnap from the back of the alternator
- the B+ cable is held in place with a 12mm nut - remove the nut and the cable
- pull the alternator forward, completely off the stud, etc.
- as you wrestle it down and out, you will probably need to remove a couple of 10mm screws holding some hard power steering lines in place next to the oil pan, to get a few extra mm of clearance.
Once you have it out, it's pretty simple and obvious how to clean it and take it apart to inspect. You can also take it to a shop for testing, but be careful with that - the test results are not always accurate.
@oldskewel Thanks for all the info! I did read that it might be the alternator as well. The battery levels were checked right before my last drive when the lights came on and stayed on. I will need to check again now that the lights are on. The alternator looks new actually. It may have been replaced a few years ago. The older gentleman I bought from had Lexus service the vehicle until the last few years of his ownership. It didn't appear replaced in Lexus service history. I think it might be an aftermarket one do be honest. So the alternator could be the culprit. I heard those types don't last long or have issues. I think I'm going to pick up a Toyota battery tomorrow just to rule that out and get rid of the Autozone Diehard battery. It's already 4 years old. I'll wait to see how that goes first. If all is the same I'll pick up an alternator and swap it out with OEM.
So I installed a new battery and lights were not on when I turned the vehicle back on. After driving to work this morning, they flashed on/off a few times and then came on and stayed on. They were on the entire trip home. It is driving normal. However, I did notice the cruise does not engage when they are on. There is no surge or dimming of lights at all.
@spuds I agree about the alternator. It is very clean and looks new. I believe it to be what you and @oldskewel are saying. Now that the cruise isn't working, I included that in my search here and found another thread with exact same issue and the alternator being the problem. I haven't had time to check new readings since replacing the battery. Next step is to buy a new OEM alternator. I'll update here as I go.
Update: After changing out the battery and checking the fuses, I still had the warning lights but car was running fine. I went ahead and purchased a Toyota/Lexus alternator from Longo Lexus parts. They are always awesome. After removing the old alternator, I noticed it was a Denso. The new one was also a Denso-remanufactured for Toyota/Lexus. Thanks @oldskewel for directions on removing it. It took just a few hours but I could have def completed it quicker if I was trying. I took my time. I drove to the store a few times and the lights haven't come back on. I'm sure it's fixed but will know more after I get back to commuting to work next week.
New alternator on right side.
Edit: Do you think the old alternator of the left is original? I just noticed that it has a stamp on it that reads 91.
Last edited by dame3780; Apr 20, 2019 at 06:51 PM.
Update: All is good! New alternator fixed my issues with all those crazy lights. I am quite happy of the warnings now as I was able to fix it without being stranded. I love this car.
Read a story about cars and 'soul' . Guy says with a BMW or MB if it has a problem the car acts like its a magic trick and expects you to figure it out.But the Lexus is different,it wants to help you find it and help you fix it.I felt that way under my car the other day.
Warning Lights-Need help
