This one confuses me... I have a 93 LS400 with 195K miles. Yesterday after being in the car and driving it for several hours, the battery warning light came on. When I increased the rpm above idle to around 1500 rpm it always went out. After searching ClubLexus last night, I think, ok - the alternator's going bad or the belt is slipping. I checked the belt last night and it seems tight. I put a voltmeter on the battery and it was about 12.6 volts without the car running after shutting it down. That would seem to me to be correct as the battery light was only on for about a minute or two (total) while idling and I was home about 10 minutes after it first came on.

Here's the weird part, today it's fine. No light, the voltage to the battery is anywhere from 13.5 to 14.3 with the engine running, all is well.

For what it's worth, I have an inverter to charge the battery in my laptop in the front cigarette lighter and I have a gps and a radar detector plugged into the backseat lighter. I have the headlights and generally the A/C is on all the time. I've had this setup for over a year.

Do you think I might have gotten the dreaded Lexus drip from the power steering pump into the alternator and overnight it cleared off the alternator? Why is this alternator working properly again? The only other thing I can think of that might have some bearing is that it was about 75 degrees yesterday and today it's 50 degrees.

Any help appreciated!

Pat

 

The battery.....battery.....battery.....is the culprit even though you think it's the alternator.
Take out the battery and have a "Load Test" done on it, pretty sure from your description that you have a bad cell in the battery.
If the battery turns up fine (I don't think it will though) have your alternator "Bench Tested" out of the car.

 

>The battery.....battery.....battery.....is the culprit even though you think it's the alternator.

Thanks, I came to that conclusion also. Changed it out and thought I had it but the battery light came on 45 mins later.

So, I swapped the alternator. Drove it for several hours yesterday and no problems.

BTW, I lost the picture that someone had posted building a cover over the alternator. The wires going into the alternator had oil inside the plastic fitting going into the alternator. This is my second power steering pump. I'd like to build a metal tray over the alternator to keep this one alive. It did last for 195K miles so maybe that wasn't it either.

 

I was just thinking of something like this!

My second alternator in 2 years is failing. Its a very slow PS leak, I have to top off the reservior about once a month, I replaced the high pressure return hose but that didnt do it last time.

I think i'll try the Lucas Pwr steering fix and try to fab some sort of shield to cover the Alternator. I just dropped over a grand on labor from bushing replacements I cant afford a new PS pump right now. I think this will work until I commit to a full replacement Pump.

Does anyone know where this picture or a tutorial for an Alternator shield would be?

Thanks!

 

The Lucas approach will not do much to fix your problem. In fact, based on my experience only, when I used it to "slow" the dripping of the fluid since it is supose to be a little more thicker than conventional PS fluid, it actually sped up the fluid loss. I went from having to fill once a month to having to fill once a week, after about 3 months. I eventually had to bite the bullet and have the PS done. I replaced my High pressure hose, used th Lucas, etc as well before I bit the bullet. I don't think that there is an "official" tutorial on an alternator shield. Some people just kinda bend a piece of aluminum over the alternator, weld it in place and then install. This may help in keeping your alternator alot longer, but you will ultimately need to get the PS fixed.