DIY:CHARGING SYSTEM FULL DIAGNOSTIC(alternator/battery) - Page 2 - Lexus IS Forum
User Tag List

 1Likes
Reply
 
LinkBack Thread Tools
post #16 of 71 (permalink) Old 02-25-2012, 03:01 AM
Addict
 
Join Date: Nov 2009
Location: San Jose, CA
Posts: 2,059
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 32 Post(s)
           
So I had my Optima yellow top battery and alternator tested at Autozone today. They found that the voltage regulator did not pass the test while everything else did. I have an audio system that is running about 600-700w rms since 60k and I'm at 94k right now.

Is it common for my car to have a bad alternator at 93k? When I ran the DC voltage test while the car was on, I believe I was getting 13.5v at idle. Shouldn't this indicate that my alternator is fine?

'03 IS300 SD TCM 5-SPD LSD
tonynca is offline  
Sponsored Links
Advertisement
 
post #17 of 71 (permalink) Old 02-25-2012, 07:54 AM Thread Starter
Immortal
 
Join Date: Aug 2009
Location: Pittsbugh PA
Posts: 19,540
Mentioned: 8 Post(s)
Tagged: 4 Thread(s)
Quoted: 78 Post(s)
           
Quote:
Originally Posted by tonynca View Post
So I had my Optima yellow top battery and alternator tested at Autozone today. They found that the voltage regulator did not pass the test while everything else did. I have an audio system that is running about 600-700w rms since 60k and I'm at 94k right now.

Is it common for my car to have a bad alternator at 93k? When I ran the DC voltage test while the car was on, I believe I was getting 13.5v at idle. Shouldn't this indicate that my alternator is fine?
600-700 wrms isn't that bad of a draw. I've been running a total of 1400 wrms with no problem for last 7-8 years. Our Denso alts are pretty durable so I am surprised. The alt may be putting out 13.5 volts, which is what mine puts out during a heavier load, but try turning on your high beams and heater on high, then take a reading and see what alt is making. Your alternator could have bad diodes and is putting out AC voltage, which is what they may be talking about. Do you even have a battery light on while car is running? If not, do an AC ripple test(as shown in DIY), and if that reads fine, your alt is not bad. My alt always has sat around 13.4 volts, and that's with the stereo on and everything else. Usually their charging system testers only test what the alt is putting out, so I'd get a second opinion or do the ripple and diode leakage test and post back your results. Also, what does the battery read with car off?

'02 IS300 MSM LSD
jasonm4 is offline  
post #18 of 71 (permalink) Old 02-25-2012, 01:16 PM
Addict
 
Join Date: Nov 2009
Location: San Jose, CA
Posts: 2,059
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 32 Post(s)
           
The battery reads 12.42 when the car is off.

'03 IS300 SD TCM 5-SPD LSD
tonynca is offline  
 
post #19 of 71 (permalink) Old 02-25-2012, 01:45 PM Thread Starter
Immortal
 
Join Date: Aug 2009
Location: Pittsbugh PA
Posts: 19,540
Mentioned: 8 Post(s)
Tagged: 4 Thread(s)
Quoted: 78 Post(s)
           
12,42 is alittle low. should be 12.6vdc or higher. If your alternator is putting 13.2vdc or high to the battery then your fine and may have a another issue. I don't see any problens yet but a low battery, that's good.

'02 IS300 MSM LSD
jasonm4 is offline  
post #20 of 71 (permalink) Old 02-25-2012, 03:07 PM
Addict
 
Join Date: Nov 2009
Location: San Jose, CA
Posts: 2,059
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 32 Post(s)
           
I'm just wondering why the regular test failed. I'll test the diodes and ripples.

'03 IS300 SD TCM 5-SPD LSD
tonynca is offline  
post #21 of 71 (permalink) Old 02-25-2012, 05:00 PM Thread Starter
Immortal
 
Join Date: Aug 2009
Location: Pittsbugh PA
Posts: 19,540
Mentioned: 8 Post(s)
Tagged: 4 Thread(s)
Quoted: 78 Post(s)
           
Quote:
Originally Posted by tonynca View Post
I'm just wondering why the regular test failed. I'll test the diodes and ripples.
Yea, their test doesn't make much sense unless it's detects a ripple.voltage, but I don't recall them being able to test that. Only charging voltage. I would take a 30 minute drive and retest maybe at NAPA or a place where they are knowledgeable.

'02 IS300 MSM LSD
jasonm4 is offline  
post #22 of 71 (permalink) Old 03-01-2012, 05:53 PM
Addict
 
Join Date: Nov 2009
Location: San Jose, CA
Posts: 2,059
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 32 Post(s)
           
I don't know what type of test they run and how it works but I figured out my problem.

Before I went in for the test, I disconnected the regulator and I noticed there was a lot of white crusty stuff inside the socket. I just plugged the regulator back in and pushed it in a bit and the car passed the test. The battery now charges to 100% @ 12.75v.

I'm going to remove the regulator plug again today and put some dielectric grease in there to prevent corrosion.

The funny thing is, I actually pressed the regulator plug in a bit more before but it still failed. I guess when I unplug and plug it back in I wiped a bit of the crusty white stuff off and there's a good connection again.

'03 IS300 SD TCM 5-SPD LSD

Last edited by tonynca; 03-01-2012 at 06:00 PM.
tonynca is offline  
post #23 of 71 (permalink) Old 03-01-2012, 06:18 PM Thread Starter
Immortal
 
Join Date: Aug 2009
Location: Pittsbugh PA
Posts: 19,540
Mentioned: 8 Post(s)
Tagged: 4 Thread(s)
Quoted: 78 Post(s)
           
Quote:
Originally Posted by tonynca View Post
I don't know what type of test they run and how it works but I figured out my problem.

Before I went in for the test, I disconnected the regulator and I noticed there was a lot of white crusty stuff inside the socket. I just plugged the regulator back in and pushed it in a bit and the car passed the test. The battery now charges to 100% @ 12.75v.

I'm going to remove the regulator plug again today and put some dielectric grease in there to prevent corrosion.

The funny thing is, I actually pressed the regulator plug in a bit more before but it still failed. I guess when I unplug and plug it back in I wiped a bit of the crusty white stuff off and there's a good connection again.

Are you talking about the 3 wire harness, mentioned in the DIY that hooks up to the alt? If so(which I think you are), good find! Luckily you found it before the alt's regulator went bad. That's not only the regulator but also the stator winding feed and feedback. The regulator is internal and the B+ stud is it's output. There definitely should be some dielectric grease on that plug and it should be tight. There's also a cover on the battery bolted connection on the stud. You should be good after a nice cleaning. Use some electronic contact cleaner and grease.

'02 IS300 MSM LSD
jasonm4 is offline  
post #24 of 71 (permalink) Old 03-02-2012, 12:24 AM
Addict
 
Join Date: Nov 2009
Location: San Jose, CA
Posts: 2,059
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 32 Post(s)
           
Yep the 3-pin connector to the regulator. When I look down into the socket I can see there's some gunk in there. I just put on some dielectric grease into the socket (on the wire connector, not alternator socket) and gave it a good insert. I'm going to stop by Autozone on the way to work to have them test it one last time to make sure I have a good connection.

I tested the regulator with a multimeter and it seems like it's doing its job. Reving to 2-3k got me a max charge output of 13.96v while being idle was 13.93v. Thanks for the troubleshooting help!

'03 IS300 SD TCM 5-SPD LSD
tonynca is offline  
post #25 of 71 (permalink) Old 05-27-2012, 08:50 PM
Deity
 
Join Date: Jul 2002
Location: MA
Posts: 10,234
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
           
Question on the 3 plug wire: the feed to the ecu, should there be a reference voltage when the alternator is properly operating or not voltage when properly operating? I had my alternator test on a bench and it came out fine but I am still getting a battery light. So I wanted to test out that ecu reference to rule out whether the my ecu went bad or the alternator.
Eminence is offline  
post #26 of 71 (permalink) Old 05-27-2012, 09:08 PM Thread Starter
Immortal
 
Join Date: Aug 2009
Location: Pittsbugh PA
Posts: 19,540
Mentioned: 8 Post(s)
Tagged: 4 Thread(s)
Quoted: 78 Post(s)
           
Quote:
Originally Posted by Eminence View Post
Question on the 3 plug wire: the feed to the ecu, should there be a reference voltage when the alternator is properly operating or not voltage when properly operating? I had my alternator test on a bench and it came out fine but I am still getting a battery light. So I wanted to test out that ecu reference to rule out whether the my ecu went bad or the alternator.
Good question and I've looked into it alittle bit, but without verifying myself yet. According to the FSM service hints:
Quote:
(B) 1-Ground: Below 1.5 volts. with ignition switch set at ON position and engine not running.
Nothing else is mentioned, nice. It would be good to find out what kind of signal that is putting into the ECU. Providing your 10A Gauge feed(IG) is good as well as the 7.5A Stator fuses, i wonder if that produces charging voltage to ground(so verify the alt really is putting out 13.2-14.8 at the battery while running in the car). It appears the feed from the 10A Guage has more to do with the battery charge light than the L signal to the ECU. Make sure you have a Gauge terminal connection(red/blue). If you lost any of those two fuses, you would get a light but the shop would read it as a good alt.

'02 IS300 MSM LSD
jasonm4 is offline  
post #27 of 71 (permalink) Old 03-22-2013, 11:58 AM
Newbie
 
Join Date: Jun 2011
Posts: 2
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
 
thanks man i haw this problem with my is 200 , great thanks
pitykot is offline  
post #28 of 71 (permalink) Old 04-04-2013, 04:19 PM
Newbie
 
Join Date: Mar 2008
Location: Calgary, Alberta, Canada
Posts: 44
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
 
I'm having what I think is an alternator issue with my 2001 is300...

First noticed it a few days ago when pulling away from a light, suddenly the voltage just dropped and all of my gauges turned off and came back on. Then when I was leaving work that same day I had everything turn off while leaving the parking garage, this time the engine shut off and I wasn't able to immediately start the car back up. The next morning I had some trouble starting the engine, it would turn over once and then all of the gauges and clock faded out. Eventually I was able to get it started but decided to take my RX350 to avoid the chance of being stuck in traffic.

I think there was a whirring noise like the alternator drive belt was slipping when things died. Will try to pick up a new serpentine belt on the way home today, already have a spare alternator to try.

Anyways I'll check my alternator and battery tonight, thank you for the how to!

2001 Lexus IS300 Automatic

K&N GenII FIPK, Xerd Headers & Megan Y-Pipe, HKS Hi-Power, Token Solutions Secondary O2 Delete, Brembo Slotted Rotors, Hawk HPS Pads, BC Racing Coilovers, Figs Polyurethane Bushings and Sway Bar End Links, SPC Front and Rear Camber Kit, Bridgestone Potenza RE760 Sport
EdDiE2k7 is offline  
post #29 of 71 (permalink) Old 04-04-2013, 04:28 PM Thread Starter
Immortal
 
Join Date: Aug 2009
Location: Pittsbugh PA
Posts: 19,540
Mentioned: 8 Post(s)
Tagged: 4 Thread(s)
Quoted: 78 Post(s)
           
Quote:
Originally Posted by EdDiE2k7 View Post
I'm having what I think is an alternator issue with my 2001 is300...

First noticed it a few days ago when pulling away from a light, suddenly the voltage just dropped and all of my gauges turned off and came back on. Then when I was leaving work that same day I had everything turn off while leaving the parking garage, this time the engine shut off and I wasn't able to immediately start the car back up. The next morning I had some trouble starting the engine, it would turn over once and then all of the gauges and clock faded out. Eventually I was able to get it started but decided to take my RX350 to avoid the chance of being stuck in traffic.

I think there was a whirring noise like the alternator drive belt was slipping when things died. Will try to pick up a new serpentine belt on the way home today, already have a spare alternator to try.

Anyways I'll check my alternator and battery tonight, thank you for the how to!
I can almost guarantee your problem is the belt because accelerating from a stop your drive belt is slipping which WILL cause a brief loss of power. Normally the alt produces very little power at idle so for you to lose power as alt rpms go up tell me the alt is not spinning right. Also, besides the obvious cracks and old age, i recommend changing the belt every 30k-40k miles.
Now your issue could also be a bad spring tensioner. Take your thumb and index finger and try to turn the belt 180 degrees. It should be difficult to do so. It's pretty rare to kill our Denso alts because they are built well, remember whatever you do, do not disconnect the battery while the car is running. If it's not the belt or tensioner post back.

'02 IS300 MSM LSD
jasonm4 is offline  
post #30 of 71 (permalink) Old 04-04-2013, 04:35 PM
Newbie
 
Join Date: Mar 2008
Location: Calgary, Alberta, Canada
Posts: 44
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
 
I bought the car with 50,000 miles and now have about 155,000 miles and have not changed the belt yet, guessing it's a bit overdue. Will check things out a bit more tonight and post back when I have more information.

Thanks for the help and quick reply.

2001 Lexus IS300 Automatic

K&N GenII FIPK, Xerd Headers & Megan Y-Pipe, HKS Hi-Power, Token Solutions Secondary O2 Delete, Brembo Slotted Rotors, Hawk HPS Pads, BC Racing Coilovers, Figs Polyurethane Bushings and Sway Bar End Links, SPC Front and Rear Camber Kit, Bridgestone Potenza RE760 Sport
EdDiE2k7 is offline  
Sponsored Links
Advertisement
 
Reply

  Lexus IS Forum > Lexus IS > DIY/tutorial forum

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Lexus IS Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself. If your address is invalid, you will likely lose access to the site.

Email Address:
OR

Log-in











Current users viewing this Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Charging you Battery Ryubomb Showroom 4 09-27-2010 04:48 AM
charging a dead battery citra Basic Help & Repair 3 03-12-2006 07:30 PM
So it's not the Battery, and not the Alternator, what could it be? Pawel The Garage 11 01-03-2006 10:13 AM
Alternator or Battery?? amadeus00 General Discussion 0 06-15-2005 08:26 AM
battery charging problem??? cruznis300 General Discussion 2 02-15-2001 12:09 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome