Electrical Issue

[AustinGT]

Hey everyone- it's been a long time (graduated college, new job, many hours, etc.) since I've been in. My apologies! I realize that forums are two way streets, and haven't been participating as such....

Still, this evening I was coming home (from voting!) and when I got into the garage the engine was under some kind of load and the radio was at a reduced volume. I turned the lights off and the radio came back to regular volume and the engine returned to a normal rpm (it was running about 75-100 rpm slow). I flipped the lights on again and the engine bogged down 75-100 rpm before the computer brought it back to normal. Is this an early sign that my alternator is headed south? I immediately hooked up the battery charger, but the battery was fully charged. Could it still be the alternator, or is there a problem with the headlights somewhere? I am hoping to jump on this before it gets to be a big problem! Thanks a lot....

Austin

[scottmcc]

Sounds like the Alternator for sure..

Have autozone test it..

[AustinGT]

I took the battery down to Autozone last night (didn't have time to take the alternator) to have them check it, and according to the machine there it is fine. I also noticed that putting on the brakes w/the lights on makes them flicker for just a second then recover... This is a long shot, but the trunk hing wires have been starting to act up recently, could that be causing an abnormal electrical draw?

I may sound like a total dummkopf, but can Autozone test the alternator without taking it out? I assumed you had to remove it before testing....

[eatingupblacktop]

Read up on the trunk harness issues. Don't know if they can cause your symptoms but they do account for many problems. Yes the alt can be tested without removal. Readings should be in the neigbourhood of:

• ~ 44 amps @ idle
  
• ~ 50 amps @ idle w load
  
• ~ 75 amps @ 2000 rpm
  
• ~ 90 amps @ 2000 rpm w load
  

Also have the ground checked.

[AustinGT]

The guy at Autozone tested the car, and said that the alternator was weaker than it should be, like roughly 70 amps at 2000 w/load, and about 13.5 volts at idle... My first reaction was to take it to the shop and have them replace it but 1) they are on vacation and 2) it doesn't look like that difficult of a job, and my dad and I have done some work on the LS before. However, I don't think I will get the Autozone alternator seeing as its made in Mexico, and I have doubts as to its longevity.... Is there a place online that has instructions on how to replace it? I checked the LexLS site but it didn't have anything. Thanks!

[eatingupblacktop]

It's not that difficult. As Lextreme describes,

Removing the Fan Belt:

The belt is very easy to remove. You will need a 14 mm socket with a 2-4" extension. The belt tension 14 mm bolt is loosen (reduced belt tension) by rotation the wrench counterclockwise meanwhile using your right hand and pull the belt of the top pulley.

Removing the Alternator:

The alternator is stabilized by one stud and one bolt. Both are 14mm. You can attach the above 14 mm nut by using a 14 mm ratrecheting or regular wrench. The lower bolt is best accomplish by using a 14 mm socket with 2-4" extension. Both the nut and bolt can be loosen from the top of the engine. The second part you will need to jack up your car on the passenger side. You need to get under the car and uninstall the engine under cover along with a 12 mm from the alternator (B Terminal Wire). The nut is somewhat above the alternator and attacking this from the bottom is the easiest. After the B Terminal is out, there is a clip behind the alternator. This clip needs to come out too.

Once everything is loosen and unattached, you can move the alternator forward to clear the top stud and lower the alternator down.

Installing alternator back is much easier and the process is reverse. This project should not take more than 2 hours and I would rate this project as a 5/10 in difficulty.

There's also this writeup:

http://us.lexusownersclub.com/forums/index...showtopic=49712

[AustinGT]

This afternoon my brother and I replaced the alternator with an OEM Denso one, and also fixed the broken trunk hinge wires. It was frustrating though because the lights are still seem to be a big load on the engine at slow idle. I did notice that the fog lights were more of a draw than the headlights.... Just wondering if there could be anything that would be still causing this given that the wiring and alternator have been fixed.....Thanks!