Generator/Alternator issues?

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The saga and learning process continues. Bottom line - my high Alternator/battery (> 15V) readings from last night seem to be bogus due to faulty multimeter (blown fuse, low battery and possibly toasted electronics on the multimeter). I had no idea b/c it gave me Volt/Amp readings and no clear/visual indication that there was anything wrong, until I started piecing clues together and questioning the damned thing.

I had considered the possibility that my higher than normal readings were due to surface charge but then read more that indicated sitting for 12h should get rid of it (which it did), and went through the procedure to dissipate that surface charge. So after eliminating surface charge as a factor, I checked my Voltage readings again when idling and now it shows even higher in 16V range but no errors or other issues on the dash. Also, the battery gauge on dash shows 14 and the service diagnostic mode shows 14.1. So now I'm wondering WTF.

Ok - full disclosure, last night I misunderstood instructions for testing for slow drain and accidentally shorted my multimeter on the battery poles a few times and smelled burned plastic and felt heat in the wires. The multimeter kept showing me readings and no errors so I assumed it was still good. Today I noticed a battery symbol on the multimeter and realized the battery was low (not sure if it had anything to do with short or not). So I got a replacement battery and figured I'd get a replacement fuse as well just in case the short blew the fuse. I opened it up to change the fuse and I saw toasted areas of the multimeter. SO... I need a new multimeter and then will redo the tests to see what's what.

Stupid me that I shorted the darned thing, but stupid design (in my opinion) that a fuse could be blown and there's no visual indicator, and stupid design that it can show you higher voltage than normal when battery is low (I found others pointing that out when I started searching on "low batter high voltage multimeter...").

I will post up the new results later... hopefully they will actually make sense :-)
 
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OK - new multimeter actually works :-)
Resting Voltage: 12.78V
Engine Running (not warmed up tho): 14.15V
Parasitic Drain: <12mA

All of those check out, right?
I'll wait till I have a second hand to retest juice when cranking and at 2k RPM.

Correct me if I'm mistaken, but at this point, doesn't seem like Alternator is a problem, or like I have parasitic drain problem, so that leads me to the starter (or a bad battery?).

Can anyone confirm that a bad starter could drain the battery with multiple failed attempts? That's the part that seems like a stretch to have taken my juice down to 9.6V. It's possible my multimeter battery was already on the fritz and that I can't trust the Voltage readings I got.
 
agaisin said:
Can anyone confirm that a bad starter could drain the battery with multiple failed attempts? That's the part that seems like a stretch to have taken my juice down to 9.6V. It's possible my multimeter battery was already on the fritz and that I can't trust the Voltage readings I got.
Click to expand...

Art, Your description sounds like a failing starter to me. Blurred by a bad multimeter. Seems like you are still in the denial phase (like I was at first on my LS). But getting stuck somewhere is no fun.

My starter on my LS400 (alsmost same engine) failed at 256,000 km. Around 160k miles. Some fail later, some fail earlier (that is what the dealer told me at the time).
 
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white_lx said:
Art, Your description sounds like a failing starter to me. Blurred by a bad multimeter. Seems like you are still in the denial phase (like I was at first on my LS). But getting stuck somewhere is no fun.

My starter on my LS400 (alsmost same engine) failed at 256,000 km. Around 160k miles. Some fail later, some fail earlier (that is what the dealer told me at the time).
Click to expand...

LOL - I refer to my process as diagnostics rather than denial :-)

If you sensed denial it's only b/c 2 batteries died on me - one old and one 10 days new. I can't find any confirmation that a temperamental starter would drain a battery to the point it won't start. That's the only question in my mind.

I will be doing the starter contacts and I will probably replace the alternator brush just so I don't have to think about it for a while.

I guess time will tell if my battery dies again after that work is done. Definitely no fun to get stuck and this is our family hauler so when we use it we depend on it...
 
OK - new multimeter actually works :-)
Resting Voltage: 12.78V
Engine Running (not warmed up tho): 14.15V
Parasitic Drain: <12mA
Click to expand...

These all look normal. So, lets consider the alternator good until there is any real evidence that it is not.

With a parasitic draw of 12mA, and assuming the headlights were't left on overnight or something similar, the battery discharge appears to be associated with attempts to start the engine.

We've been concentrating on starter contacts problems, because they are common, but this is not consistent with multiple start attempts draining the battery. There is more than one way that the starter could have failed, including modes that would draw heavy current when you switched to crank position.

Bottom line is that everything you've posted points to the starter, and suggests a terminal failure rather than the more common contacts-only failure.
Fairfax Auto Parts have a good reman starter for around $170. It was in stock when I needed one recently, so give 'em a call. The R&R is a few hours, but no rocket science involved.
 
APKhaos said:
These all look normal. So, lets consider the alternator good until there is any real evidence that it is not.

With a parasitic draw of 12mA, and assuming the headlights were't left on overnight or something similar, the battery discharge appears to be associated with attempts to start the engine.

We've been concentrating on starter contacts problems, because they are common, but this is not consistent with multiple start attempts draining the battery. There is more than one way that the starter could have failed, including modes that would draw heavy current when you switched to crank position.

Bottom line is that everything you've posted points to the starter, and suggests a terminal failure rather than the more common contacts-only failure.
Fairfax Auto Parts have a good reman starter for around $170. It was in stock when I needed one recently, so give 'em a call. The R&R is a few hours, but no rocket science involved.
Click to expand...

Ok - I hear what you're saying and here's a followup question. I've read that bad diode in alternator can cause current to leak and drain a battery. The test I saw was to check for AC Voltage when the car is off - if there is any then you have a bad alternator diode.

Well without fully understanding I did change the new multimeter to AC and tested and got readings alternating from ~33V to ~1.7V and back to ~33V etc... Is this evidence that I have a bad alternator diode draining my battery? Also from what i read on the bad alternator diode - it can still charge the battery and test fine for charging but still drain the battery when the car is off.

From here:
Diagnosing A Car Battery That Runs Down
"Sometimes a bad alternator diode can cause a car battery to run down. A good diode should only pass current in one direction. If it leaks current in the opposite direction, it may keep the charging circuit on when the engine is not running, causing the battery to run down. This kind of problem can be diagnosed several ways. If your voltmeter has an AC (alternating current) scale, switch to that scale and observe the charging voltage with the engine running. If the meter shows any AC voltage, one or more diodes are leaking and the alternator needs to be replaced."
 
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You said:
Parasitic Drain: <12mA
Click to expand...
The interwebz said:
A good diode should only pass current in one direction. If it leaks current in the opposite direction, it may keep the charging circuit on when the engine is not running, causing the battery to run down.
Click to expand...

A failed diode in the regulator could provide a path to discharge the battery when the engine is not running. The leakage current in this case would be several amps. That's why the parasitic drain is an important test.
Here's how to test it:
- Car off
- Remove the positive battery lead carefully
- With multitester on DC Amps setting connect one lead to the positive lead and the other to the positive terminal on the battery. Any leakage [parasitic] current now passes through the multitester. Read the current. Check you scale carefully to be sure you are reading the value value [unless the tester is autoscale, of course].

If you are still reading 12mA, your alternator diodes are good. 12mA is a normal maintenance load for the few things that are still powered when the car if off.

Hope this helps.
 
According to Advance Auto's diagnostic equipment the battery, starter and charging system tested ok and there was a 'suspect' drain of 1.5A.

Battery Test showed voltage was 12.93V and CCA was 1370 (rated at 740).
Starter test showed starting Voltage was 11.96 and drew 110A to start, and it took 875ms.
Charging test showed 13.7V No load, and 13.65 with load (headlight and blower at H).

I assume the starter voltage and draw is reasonable?
I suspect the Alternator numbers are on the low end of OK but still ok. (I do get higher V readings when car is first started b/f car has warmed up).

When I check for parasitic draw I am getting fluctuation - as high as 1.2A and as low as 30mA where it's at 30mA for a length of time (at least a few minutes) and then spikes to 1.2A for a short period of time (at least 10 seconds). I have not pinned down the cycle but after 34 minutes (periodically checking in) I get the same cycle of 30mA most of the time but then it spikes to 1.2A for at least 10 seconds and back down to 30mA for a while.

Here are my conclusions:
1) Alternator - not overcharging or undercharging. Perhaps it could use brushes, but it is outputting sufficient Voltage to charge the battery.
2) Alternator - no bad diodes leading to alternator draining the battery. I tested for AC voltage with car on and get 8mV.
3) Starter - motor tests good. Unless a bad motor could lead to intermittently draining battery during a start. I.e. if a large draw were due to bad coils or bad bearings leading to more amps to start I would expect that every start would draw abnormally large current. True?
4) Starter - contacts still suspect. (any more no starts and I'll be replacing either starter or contacts for sure)
5) No shorts in electrical system - If I had a short it would consistently be drawing that current right?
6) 1.2A is definitely not acceptible if it were consistent but it's not consistent... Does anyone else get an intermittent draw like this - would love to see someone else's numbers.
7) 30mA for a consistent draw is well within reason from what I've read.
8) I'll still try and track down what's causing that cyclic 1.2A draw (factory alarm system, two vaistech units - sat and ipod, ipod is always plugged into vais input, can't think of anything else out of the norm).
9) I will keep my eye on the starter - and if I have any more issues I will not try to restart more than once. I will immediately take V of the battery to determine if battery is the problem or if starter is draining battery intermittently.

Make sense? Anyone have any other ideas?

Question - I have noticed that every time I disconnect the negative terminal for a few minutes, the first start fails. Is this normal or is this telling me something? (Note my driveway where the LX sits every day is on a nice incline) OBD scanner doesn't give me any DTCs but I didn't whip out the techstream yet. Is it possible that my engine is harder to start for some reason - especially if I leave it for a week b/w starts - could this be an engine related issue? Not quite siezing but early signs? Perhaps bad or dirty spark plugs or something else going on with ignition system?

Also - to help monitor the situation, I ordered the BatteryMole (Amazon.com: BatteryMole Car Battery Warning System (12 Volt Automobile Battery Monitor with Battery Failure Prediction Logic). Made in USA: Electronics) and will keep an eye on things. This is more than the typical battery monitor (like Equus 3721 which I ordered for another car) - unlike the equus which just shows battery voltage, this battery mole is more sophisticated and does the following (http://4peaks-tech.com/product_monitor.htm):

Displays the following information:
- Charge State (SoC) of the Battery
- Engine Start Voltage
- Engine Start Time
- Battery Voltage
- Alternator Voltage

Detects the following alarm conditions:
- Low Battery (SoC) Charge
- Weak Engine Start Voltage
- Slow Engine Start Time
- Alternator Overcharging
- Alternator Undercharging
- Low Battery Voltage
 
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bump...
can bad starter only sometimes draw too many amps?
is 8mV AC with engine running indictive of good or bad alternator diodes? (i.e. had seen that any AC voltage at the battery indicates bad alternator diodes)
is 1.2amp intermittentl draw enough to drain batteries in a week?
any idea whether 1.2A intermittently is normal or what it is from?
what kind of draw do others see with everything off (multiple readings required since this is not constant.
 
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Plausible Explanation?

OK - was talking through this with a friend that's been around the automative block and here's what he pointed out.

My starter, alternator and battery all check out. My old battery died but my driving habits had changed significantly the month before (from driving i.e charging every day to driving/charging just the weekends). So the old battery dying is explainable and understandable. He didn't think the draw I was anything to be concerned about.

The problem was the new battery dying after 10 days. Well - he points out that the AGM battery was on the shelf for (5) months (manufacture date was 10/2011 iirc) and it wasn't driven enough to fully charge b/c I may barely have driven it over that 10 day period and most definitely it was not enough to bring it back to sufficient/full charge. So not starting 10 days later on a new battery that was on the shelf for 5 months isn't a surprise.

Sounds logical to me given that everything else seems to check out.
 
Art,

You stated you have found a variable current parasitic draw. By chance do you have an aftermarket alarm installed? Sound system amp(s)?
 
spressomon said:
Art,

You stated you have found a variable current parasitic draw. By chance do you have an aftermarket alarm installed? Sound system amp(s)?
Click to expand...

I have the factory alarm and the factory Mark Levinson sound system. Only aftermarket items I know of (I'm second owner) are the two VAISTech modules (one for satellite and one for ipod interface).

As far as the parasitic draw, what I saw was 30mA most of the time and then some short period of 1.2A every few minutes. It was not a constant draw of 1.2A. The only constant draw was 30mA and that is well within normal ranges by all acounts I've seen. And the 1.2A seemed to be every few minutes.

Unfortunately I did not identify the pattern or the source - since it was so intermittent I would either need to sit there for 30 minutes or get a multimeter with data logging :-) to identify the pattern. And then to identify the source I would need to wait at least that amount of time after each fuse I pull to see if the draw went away or changed. Also, I believe the car needs to go to 'sleep' first b/f relying on the numbers b/c for some period of time after use the car will have more draw than normal. So assume it's 20 minutes to sleep (I don't know that for certain though), I need to first wait 20 minutes and then start my observations. On top of that - if my hood is open does that keep the car from going to sleep?

I think I can explain everything that I've seen and I'll be keeping an eye on things for the near term. Since I will have a battery monitor plugged in at all times, I'll know ahead of time if my battery's getting drained.

First dead battery - old age and neglect (not maintained properly and not driven as frequently for the month prior after I stopped daily driving it).
Second dead battery - 5 month old 'new' battery not driven enough after install to get back to full charge.
Wacky readings - either low multimeter battery leading to inaccurate readings, fuses blown leading to no readings, initial misunderstandings of basic electrical principles, auto range feature that causes numbers to jump from mV to V or mA to A without realizing it jumped ranges and misinterpreting the numbers.
 
agaisin said:
Also - to help monitor the situation, I ordered the BatteryMole (Amazon.com: BatteryMole Car Battery Warning System (12 Volt Automobile Battery Monitor with Battery Failure Prediction Logic). Made in USA: Electronics) and will keep an eye on things. This is more than the typical battery monitor (like Equus 3721 which I ordered for another car) - unlike the equus which just shows battery voltage, this battery mole is more sophisticated and does the following (http://4peaks-tech.com/product_monitor.htm):

Displays the following information:
- Charge State (SoC) of the Battery
- Engine Start Voltage
- Engine Start Time
- Battery Voltage
- Alternator Voltage

Detects the following alarm conditions:
- Low Battery (SoC) Charge
- Weak Engine Start Voltage
- Slow Engine Start Time
- Alternator Overcharging
- Alternator Undercharging
- Low Battery Voltage
Click to expand...

I have to follow up on this - while the product is a great idea, it also isn't able to provide all the data on all cars as they explain in the FAQ and manual. At least for my 05LX, all I get is the battery/alternator voltage when the vehicle is running and the engine start time (it only displays this when the vehicle was off >4 hours). Looks like our outlets are turned off when the vehicle is off, and turned off while the vehicle is starting (?), so the starting voltage and state of charge don't display for me.

Therefore, I decided to return this product in favor of the simpler/cheaper Equus 3721 Battery Monitor Amazon.com: Equus 3721 Battery and Charging System Monitor: Automotive for just $15 instead of $40. Also, I realize now that Alternator output goes down after the engine/engine bay/alternator warm up, and the service diagnostic mode's Voltage reading appears accurate (to only 1 decimal point). However this is always in my face and will promptly alert me to any issues whereas the Service Diagnostic mode is not something you switch to/away from while driving unless you have to (it 'reboots' the nav etc).
 
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