Battery Warning Light And Headlight Leveling Light On Please Help

[hardhat]

2000 Lexus LS400 with 126k miles. Has been very reliable. Went on vacation 4 hours from home and noticed that battery was weak. Would start slowly. After it got running, it was fine. I did notice a few weeks ago that the battery got weak while sitting idling for a long duration (radio quit working), but perked back up when driving. I thought the battery going bad. Put a new one in. Everything fine for 2 weeks. Then today the headlight leveling warning came on and the battery light came on. I have not driven the car enough to tell what is going to happen. Is it a headlight leveling motor shorted out draining the battery? Dead alternator that has been gradually going bad?

Thanks,

Larry

[curiousB]

Sounds like alternator isn't charging enough. Measure battery voltage on battery terminals with engine running and several items switched on (headlights, foglights, AC blower, rear window defogger, tunes and so on). If its below 13.3V you have issues.

[landar]

Sounds like alternator isn't charging enough. Measure battery voltage on battery terminals with engine running and several items switched on (headlights, foglights, AC blower, rear window defogger, tunes and so on). If its below 13.3V you have issues.

Agreed. And is the 2000 susceptible to a leaky power steering unit as are the earlier models?

[TA in KC]

Agreed. And is the 2000 susceptible to a leaky power steering unit as are the earlier models?

I don't think so- I think this is the reason the fluid reservoir was no longer mounted directly on top of the power steering pump on the 98-00 LS.

[azure]

Car runs out of power shortly after these lights come on, so be careful.

[RX400h]

On 6/10/2011 at 11:39 AM, curiousB said:

Sounds like alternator isn't charging enough. Measure battery voltage on battery terminals with engine running and several items switched on (headlights, foglights, AC blower, rear window defogger, tunes and so on). If its below 13.3V you have issues.

Agreed - check the alternator.

[vissine]

This is an old thread. Who is actually having problem and does need help?

[THEOOOGIE]

On 7/24/2020 at 7:37 PM, vissine said:

This is an old thread. Who is actually having problem and does need help?

I am , 2000 Lexus ls400 same as OP alternator is 3 days old , I did one 100mph pull then this happened 

[1990LS400]

14 hours ago, THEOOOGIE said:

I am , 2000 Lexus ls400 same as OP alternator is 3 days old , I did one 100mph pull then this happened 

A fairly common cause of the problems described in this thread is a starter drawing excess amps.  Have your starter checked for current draw.  The starter in the 2000 LS400 I drove for 11 years developed this problem at something like 150,000 miles.  It was a lot of years ago but I seem to remember that having it replaced cost around $800 at an indie repair shop specializing in Lexus.    

[mikaelse]

On 3/27/2021 at 12:41 AM, THEOOOGIE said:

I am , 2000 Lexus ls400 same as OP alternator is 3 days old , I did one 100mph pull then this happened 

A bit late but a good suggestion is to buy a mobile charger that doubles as a voltage meter for the 12 V socket. I paid 15$ or so.  Then you can see what the battery is doing. 

It should charge up most of what start took in minutes and show a bit above 13 V at least if it is in normal state. If depleted it could show less.  Batteries charged to <70% age fast. Use a charger if that should happen. 

 

[z_johnq]

I had exactly the same issues on my 95 LS400 (with about 125k miles) a couple of weeks ago. The battery warning light came on and off for a few days, in fact, it was more off than on. I know my power steering pump is leaking but the alternator pulley spins smoothly and it looks clean. But last week, the car was dead on the way back home. It was dead again after a couple of jump-start. It looked obvious it was the alternator. I bought a brand-new battery so I could drive home without calling for a tow truck. The battery warning light had been on since the new battery installed. 

It took me about 2 hours to take off the bad alternator. I'm waiting for the replacement to reach me so I can install it.

I don't want to fix or replace the power steering pump. Is there any way to keep the leaking p.s. fluid from dripping down to the alternator? Probably the leaking fluid damaged the voltage regulator or other parts, even the mechanical parts working fine.

Thanks in advance.

[z_johnq]

The alternator has been replaced and everything looks fine now. No more battery warning light so far. No sure how long it will last since the power steering pump is still leaking. 

[RX400h]

Why don't you want to fix the power steering pump? Does it require special tools? Have you called around to see what the cost would be? Leaking oil is bad for the environment. 

[z_johnq]

Thanks for the suggestion. But the leaking is around p.s. pump area. What if the pump is replaced, but leaking is not stopped? It is not easy to pin-point the location of the leaking. I checked a few previous posts, there may be quite a few parts that cause leaking. The aftermarket pump cost only around 70 bucks. Let me check the leaking spots first. 

I guess the leaking on my car won't cause pollution because it's very light leaking.

[RX400h]

Mechanics will often add an ultraviolet dye to the fluid to pinpoint leaking. 

[z_johnq]

This is a good idea! But is the dye available in any auto parts stores? I heard of something like that can be put in a cooling system to spot leaking, not in p.s. systemp.

Thanks RX400h!