What Is Wrong With My 02 Ls 430?

[Mlachake]

The lights are flickering (dome, day driving and rear lights). The vehicle has labored acceleration from stop like on a red light with a feeling like it's stalling. The air conditioner/heat blows intermittently (in sequence with flickering lights... paa paa paa). The filckering alternates, sometimes while the car is stopped and sometines when the car is driving... never both.

Sometimes the moon roof will close halfway and then reverse and stay open, so does the front passenger window. The vehicle has a rough idle and sometimes lacks enough power. This all started after the alternator died and I had it replaced.

I was driving when the battery got drained, the controls seemed to freak out, then the headlights went out before the car came to a stop. The car was without power for 24 hours. Any advise will be very welcome! Thank you. :(

[landar]

It all sounds like an electrical power issue as you suspect. Now, it might help to back up a little and let us know how your car was behaving BEFORE the alternator change out. It could be that the alternator was not the root problem and it is something else.

Of course the battery and post connections/cables are always suspect in a situation like this. Sometimes, it is as simple as someone forgot to tighten down a connection or properly clean a connection. Could be that whoever installed the new alternator missed tightening a connection(s). Could be that the battery is just shot (very common).

If it were mine, I would pull out my voltmeter first thing and check the voltage at the battery while it is running. I would turn on some heavy power draws (like lights, rear defroster) and see if the voltage fluctuated. I would also check for any AC (alternating current) component on the system. Could be that the new alternator is bad. Not likely... but it does happen. The battery and poor connection(s) is where I would start the search along with the voltage check. Check at the battery posts AND at the clamps.

Keep in mind that it is probably something very simple such as a loose/dirty connection or a bad battery.

[SW03ES]

The new alternator you had installed, was it new, remanufactured, OEM, aftermarket?

[curiousB]

..."This all started after the alternator died and I had it replaced. "...

It happened when? immediately as you picked it up? Within days,weeks, or months of hacving it done?

First option is to take it back to guy who "fixed it".

Is belt on? Is charger wire bolted firmly on side of alternator (disconnect negative post of battery before you get down there with tools)? Battery post clean and tight?

[landar]

I would also add that I would not drive it much in this condition. Something is seriously spiking(up/down) the voltage on the system and the electronics, which are expensive and delicate, are being subjected to that spiking. Not good for their longevity.

[Mlachake]

Thank you kindly for all your responses. I may have made a mistake by saying the issue developed after I put in a new alternator. My apologies. I was reminded that I complained about the issue before the alternator died. I also replaced the spark plugs thinking I had a faulty one.

The alternator is an after market and is charging just fine. I went by the local Lexus dealer and talked to a consultant, he suggested I bring it in next week and go on a road test with a technician.

One mechanic had mentioned a bad coil... well I won't know until the dealer goes through it. Meanwhile the mystery continues.

[landar]

A bad coil (you have 8 of them) will not cause flickering lights as you have described. Again, check connections very carefully(battery cables and grounds) and perhaps try a different battery... especially if it is older than three years (could be an intermittent cell). Almost sounds like the alternator was changed out to try and fix this problem but did not(?)