Truck is dead, looking for suggestions.

[someotherguy]

Load tests can give you false confidence that your battery is good.

I don't disagree, and I have had questionable results with a load tester. However, it is part of the diagnostic process.

It seems like the old school professional load test equipment (like a Sun VAT-38) was more intensive than these little handhelds that are more common for DIY'ers. I tried to find some data about what their amp rating was but nothing was readily apparent.

Example, my OTC 3181 is only 130A - something I didn't even notice until someone here mentioned it. A suspect battery I tested with it recently showed 11V first time around, which is indicated as "good" on the scale, but a repeat test put it down to 9V. I don't consider 11V good, of course, so it's puzzling why the device is marked that way. At any rate the battery was obviously bad showing results like that after a full charge, and I got it warrantied out.

Symptoms on that battery were failure to start - very slow dragging starter and then rapid clicking of the solenoid, loss of radio settings, etc. but would crank almost immediately after just a couple seconds on the jumper cables, and would start relatively normally several more times afterwards before failing completely again.

You must be registered for see images attach

You must be registered for see images attach

Richard

 

[Road Trip]

Load tests can give you false confidence that your battery is good.

With my old battery I had to jump start it any time I drive it. After driving around a bit I could always shut it off and restart it though no issues. I put a tester on and it showed more than enough CCA (which is all a tester is looking for) but after replacing the battery I haven't had an issue since. The drain was so bad that after a day it wouldn't start but after replacing it with one that wouldn't drain I was good to go.

You have described a battery that, instead of an external parasitic draw flattening it, the battery was
self-discharging itself in one or more cells. This is a kinda rare failure, but I've troubleshot
this a few times over the years. The easiest way to troubleshoot a battery like this is to fully charge it,
disconnect the cabling, and after a day or so recheck the charge. A good battery will sit for
a couple of weeks and still pass a load test (healthy lead/acid batteries lose ~1% charge per day) ...but
a self-discharging battery will go flat in in a day/weekend, all by itself, even with nothing connected to it.

Years ago I read an article out of a industry mag detailing all the different ways a 12v battery can fail,
but I can't find it. So instead, here's a drawing of a single 2.1v lead/acid cell, showing the positive &
negative plates suspended in a sulfuric acid solution:

You must be registered for see images attach

When the battery is new, the porous lead is attached to their respective plates, and the bottom of
the cell is clean. But when things go wrong, the vertical sheets start shedding their lead, and you
end up with a 'conductive mud' on the bottom of the cell, and if enough accumulates, this creates a
low amperage short-circuit between the suspended positive & negative plates, where the battery
self-discharges over a relatively short period of time.

Again, this is a pretty rare failure. When I've seen it, either the battery had been discharged in cold
temps and froze (charged batteries won't freeze) or the battery was in a vehicle regularly driven over
washboard dirt roads, etc. Doesn't mean that this can't happen to a battery on a pampered trailer queen,
but this would suggest a manufacturing defect where the porous lead wasn't properly bonded to the underlying
positive or negative plate.

So yeah, I can absolutely see a battery that discharges itself, has to be jumped to start, then works fine as
long as you use the vehicle, will now pass a load test...and then after sitting day or so, reverts back to the
no-start condition. And a good replacement battery does none of this nonsense.

Load testers prove/disprove that a fully charged battery has the chemical brawn to turn chemistry into big current
with minimal voltage sag. But as you stated, they don't test for any self-discharging cells. And I'm in agreement
with Richard, for a good 'real work required' load tester is a valuable troubleshooting tool, but it's only part of
a complete diagnostic process.

Disclaimer: I state this having been formally trained on an old Sun VAT-40 back in the day.
But as a hobbyist I get by on a consumer-grade '500 Amp' carbon pile load tester. I've used
it so many times on known-good vehicles that a weak/marginal battery stands out by how
quickly the voltage caves when I start cranking down on the carbon pile knob and pull some amps.

It's not as robust or possibly even as accurate as the old Sun setup, but it's never lied to me. And
those modern lightweight impedance-based testers at the parts stores *have* lied to me on more than one occasion.

The bottom line is that there is so much less guessing about all things battery when I finally broke down and gave
myself an old-school style load tester. It has paid for itself many times over by telling me which batteries to keep
(and look elsewhere for the problem) ...and also identifies which ones have lost their chemical mojo and
should be immediately retired from service.

FWIW --

 

[95burban]

What kind of battery is it? I don’t want to make this a “who makes the best battery” thread but if it’s an optima I’ve seen several cause very erratic electrical issues.

 

[Beason]

thanks guys for all the suggestions. i do appreciate all of your time,

I want to reiterate though. this went dead INSTANTLY. it drove 100% fine yesterday, this morning when i turned the key, the entire dash woke up, seatbelt buzzer, A/C blower blasting.

when i tried to start it COMPLETLY SHUT OFF. no power at all. no horn, no a/c, even the door locks would not work.

this is not a parasitic draw, or old batter that is low.

its as if the battery is disconnected.

I have only ever seen this with bad terminals, from either corrosion or lose connection, or bad/corroded main ground. Everything under the hood looked completely fine last week though. I rebuilt the entire A/C system, so i was right around the battery for hours.

 

[Rock Hard Concrete]

Ignition switch? Power in acc, but nothing in run and if the battery tests good, makes me think it has to be the ignition.

 

[someotherguy]

You have described a battery that, instead of an external parasitic draw flattening it, the battery was
self-discharging itself in one or more cells. This is a kinda rare failure, but I've troubleshot
this a few times over the years. The easiest way to troubleshoot a battery like this is to fully charge it,
disconnect the cabling, and after a day or so recheck the charge. A good battery will sit for
a couple of weeks and still pass a load test (healthy lead/acid batteries lose ~1% charge per day) ...but
a self-discharging battery will go flat in in a day/weekend, all by itself, even with nothing connected to it.

Years ago I read an article out of a industry mag detailing all the different ways a 12v battery can fail,
but I can't find it. So instead, here's a drawing of a single 2.1V lead/acid cell, showing the positive &
negative plates suspended in a sulfuric acid solution:

You must be registered for see images attach

When the battery is new, the porous lead is attached to their respective plates, and the bottom of
the cell is clean. But when things go wrong, the vertical sheets start shedding their lead, and you
end up with a 'conductive mud' on the bottom of the cell, and if enough accumulates, this creates a
low amperage short-circuit between the suspended positive & negative plates, where the battery
self-discharges over a relatively short period of time.

Again, this is a pretty rare failure. When I've seen it, either the battery had been discharged in cold
temps and froze (charged batteries won't freeze) or the battery was in a vehicle driven over washboard
dirt roads, etc. Doesn't mean that this can't happen to a battery on a pampered trailer queen, but this
would suggest a manufacturing defect where the porous lead isn't properly bonded to the underlying plate.

So yeah, I can absolutely see a battery that discharges itself, has to be jumped to start, then works fine as
long as you use the vehicle, will now pass a load test...and then after sitting day or so, reverts back to the
no-start condition. And a good replacement battery does none of this nonsense.

Load testers prove/disprove that a fully charged battery has the chemical brawn to turn chemistry into big current
with minimal voltage sag. But as you stated, they don't test for any self-discharging cells. And I'm in agreement
with Richard, for a good 'real work required' load tester is a valuable troubleshooting tool, but it's only part of
a complete diagnostic process.

Disclaimer: I state this having been formally trained on an old Sun VAT-40 back in the day.
But as a hobbyist I get by on a consumer-grade '500 Amp' carbon pile load tester. I've used
it so many times on known-good vehicles that a weak/marginal battery stands out by how
quickly the voltage caves when I start cranking down on the carbon pile knob and pull some amps.

It's not as robust or possibly even as accurate as the old Sun setup, but it's never lied to me. And
those modern lightweight impedance-based testers at the parts stores *have* lied to me on more than one occasion.

The bottom line is that there is so much less guessing about all things battery when I finally broke down and gave
myself an old-school load tester. It has paid for itself many times over by telling me which batteries to keep
(and look elsewhere for the problem) ...and also identifies which ones have lost their chemical mojo and
should be immediately retired from service.

FWIW --

That's some nice test equipment there. We had the VAT-38 at the shop I was helper at back in the late 80's. It would bring a marginal battery to its knees, quickly. That 500A Chicago unit has my little OTC looking like the toy that it is.

Richard

 

[Road Trip]

That's some nice test equipment there. We had the VAT-38 at the shop I was helper at back in the late 80's. It would bring a marginal battery to its knees, quickly.

Funny how the official test is set up where you pull 1/2 of the CCA rating for 15 seconds, the tone sounds, you read the voltage,
rate/derate the voltage you observed by the battery temp, and there's your answer:

You must be registered for see images attach

The funny thing is that after testing so many batteries over the years (both good & bad)
you only need to watch the meter for a few seconds and you will already know if the battery is
good or bad. On really good batteries the voltage is stiff, and barely drops as you crank
in additional load.

But on a weak/marginal battery (even ones still cranking the engine over, albeit slowly) the
voltage sags immediately, and the more amps drawn the lower the voltage in a linear relationship,
because the total amount of power that can be delivered by the battery under test (P = I x E)
has been reached early on.

So actual real-world accurate testing becomes a 'feel' thing, but once you get this experience
you can make rock-solid decisions in less than a minute's detour due to load testing. (Including
hooking up the tester & running the procedure -- it's that fast.)

That 500A Chicago unit has my little OTC looking like the toy that it is.

Richard

I'll be the first to tell you that your OTC tool is a higher quality piece of test
equipment than my hobbyist-level load tester. IIRC, back in the day the
'130 Amp' OTC tester was primarily used to perform alternator output testing,
and it was very good for that. For example, an alternator with 1 or more
wounded diodes in the rectifier bridge would put out some, but not all of the
necessary current, and your tool could easily show an alternator that would
cave under demand well before it's rated output. (alternator rectifier bridges)

One more thing about battery testing. From my comments I'm on record for
preferring 'real work' resistance-based DC load testing, but at the same time
turning untrained people in parts stores loose with these spendy, old-school
testers could prove to be a possible safety issue.

So there was a need for a tester that could reliably infer the health of a battery without
requiring 100s of amps of current to be drawn. And this is where the 'modern' handheld
load tester came to be.

Paraphrasing Schurkey, the modern handheld tester shouts some Van Halen into
the battery, listens to the echos, and gonkulates the battery status. Here's a succinct
technical overview comparing old brute force vs modern finesse testing. (Battery University article)

****

I know that when I'm talking about high voltage behavior in the Ignition system I always hedge
my bets, for the higher the voltage, the more predicting electricity is like herding cats. But when
it comes to 12v batteries, thanks to the sheer quantity of knowledge out there one can be much
more decisive, and with the right tools, can easily tell if a battery has more than enough suds for
your next cross country excursion, or it's past due for retirement & driving to the neighborhood
ice cream stand is an iffy proposition. :0)

****

All good stuff. Definitely a good conversation to have in public here in the GMT400 forum thanks
to all the claims/counterclaims on this topic out on the interwebs. And especially since new
replacement batteries are now a $$$ price of admission. (!)

Cheers --

 

[Road Trip]

thanks guys for all the suggestions. i do appreciate all of your time,

I want to reiterate though. this went dead INSTANTLY. it drove 100% fine yesterday, this morning when i turned the key, the entire dash woke up, seatbelt buzzer, A/C blower blasting.

when i tried to start it COMPLETLY SHUT OFF. no power at all. no horn, no a/c, even the door locks would not work.

this is not a parasitic draw, or old batter that is low.

its as if the battery is disconnected.

I have only ever seen this with bad terminals, from either corrosion or lose connection, or bad/corroded main ground. Everything under the hood looked completely fine last week though. I rebuilt the entire A/C system, so i was right around the battery for hours.

Greetings Beason,

I have personally troubleshot the exact same symptoms on both side terminal and conventional post battery designs.

In order to determine exactly where the power interruption is occurring in the electrical system, a careful focus on the
symptoms will point us in the right direction.

* For example, the more global the failure, the closer to the battery the fault will be. (Keep this in mind for later.)
* A little further away, a specific fusible link will affect only a section of the electrical system.
* An individual relay or fuse will affect a specific circuit, but not affect all the rest.
* And the troubleshooter must also keep in mind that some circuits are "Hot Always". (Horn, brake lights, headlights, etc)
* For comparison purposes, one or two of the "Hot Always" are the input power supplied to the Ignition Switch. The
Ignition Switch is in turn responsible for removing power from large parts of the vehicle on demand using the key. (Radio, fans, ignition, computer, etc)

So let's pull all this theory together via the 'total power loss after attempted cranking':

Drove the truck yesterday, for multiple stops, with no issues at all. made it home and parked without any indication of issues.

This morning went to leave for work.

turn key to acc, dash lights up, A/C starts blowing, normal.

turn key to start, everything goes dead. no lights, no blower, cant even lock the doors.

OK. We start off with the entire vehicle electrically operational. When the key is turned to START,
an initial rush of current is drawn. But due to a marginal connection at the battery, this sudden high current
flow opens the path that was supporting all the smaller electrical loads, and like the old camera flashbulbs,
somewhere was a bright flash, localized heat, and then exactly nothing. ALL POWER TO THE VEHICLE IS LOST.

EDIT: This isn't a bad starter solenoid, for that would only affect the circuits fed by the IGN A fuse. And it isn't a bad
Neutral Safety Switch or the control side of the Starter Relay, because that would only affect the CRANK fuse.
And it isn't a starter drawing more current than the battery can supply, for that symptom is the headlights
dimming excessively while cranking, but the headlights/dome lights, etc returning to near normal brightness once
the cranking is stopped.

Another item off the suspect list is the Ignition Switch, for when this specific failure happens, not only are the ignition switch-related
loads dead, but also all the other "Hot Always" circuits upstream of the Ignition Switch are also dead. (!)

The telltale, especially when troubleshooting a sudden complete loss of power (and it's impossible to completely drain a
fully-charged lead/acid battery immediately) is to turn the headlights on and then attempt to crank the engine. IF the headlights
stay bright while you are attempting to crank the engine, then we have an open circuit that only affects the cranking function.

But if the headlights suddenly go dead, plus you get no response from turning the key to START, then we are currently
experiencing an electrical circuit open in a spot where ALL the circuits have suddenly lost power.

****

This can and does happen to both conventional post and side terminal batteries, but assuming that you are running
the stock side post terminals in your vehicle, I can explain what happens the majority of the time. It seems that
there can be a tolerance stackup, where the factory cable bolts (with the 8mm hex head) are too long and bottoms
out inside the threaded battery hole *before* a solid electrical connection is made with the cable. I've seen it where
I'm close to stripping the soft lead threads in the battery, and yet I can still twist the power cables side to side?

Sometimes this is due to the cable ends compressing just a bit, while other times the problem shows up coincident
with a new battery swapped into the engine bay. (And the new battery bolt hole(s) are too shallow for the stock bolt.)
And of course there's always improper bolt substitution over the years by some unknown mechanic who grabbed
whatever was in the used bolt bucket at the time.

For what it's worth, here's a thread where the owner was performing an engine swap, and suddenly he was also
experiencing a global loss of power immediately after attempting to crank over a recently installed 5.7. Here's
the reply where he finally troubleshot it down to the problem part: (bad battery bolt, clean but still no joy)

In addition to bottoming out due to a battery manufacturer getting the depth wrong or the starter cable
compressing a bit, the factory bolt design forces me to tighten into soft lead while simultaneously trying to get
a secure electrical cable connection. There are now 2 possible upgrades to avoid these issues:

1)

You must be registered for see images attach

This is a divide and conquer solution. You first torque the above into the battery using the factory spec. (So you don't pull the lead threads.)

Now you can put a large wrench on this brass stud and keep it from turning while you tighten up the power cables
with the smaller fine-threaded nut. (As a side benefit, this also makes it easy to attach jumper cables if need be
down the road.) With my battery set up with a pair of these, I get a solid connection at the battery and I can
then tighten my power cables until they are 'can't fail in flight' tight *without* overstressing the lead threads
in the batteries.

Better than new...and that doesn't happen very often.

2) The other solution is using a longer bolt plus a nut. You siimply thread the bolt in gently until it stops,
and then use the nut to apply the necessary clamping force onto the power cables. Similar to replacing
head bolts with studs and nuts on cylinder heads. Schurkey demonstrates this in reply #91 to the other
thread mentioned previously. (Bolt & nut setup for battery cable connections)

****

That's all I got. The symptoms of a global electrical power loss after attempted high-current draw points
us to a connection issue right at the battery. (Or of course where the main ground connections are.)
This same global power loss allows us to remove the Ignition Switch and other non-global connections
from the suspect list.

And we also have a simple better than new solution to help resolve the problem, and more importantly,
prevent it from re-occurring.

Best of luck. And please reply back with what you discover to be the root cause/final fix.

 

[Beason]

Greetings Beason,

I have personally troubleshot the exact same symptoms on both side terminal and conventional post battery designs.

In order to determine exactly where the power interruption is occurring in the electrical system, a careful focus on the
symptoms will point us in the right direction.

* For example, the more global the failure, the closer to the battery the fault will be. (Keep this in mind for later.)
* A little further away, a specific fusible link will affect only a section of the electrical system.
* An individual relay or fuse will affect a specific circuit, but not affect all the rest.
* And the troubleshooter must also keep in mind that some circuits are "Hot Always". (Horn, brake lights, headlights, etc)
* For comparison purposes, one or two of the "Hot Always" are the input power supplied to the Ignition Switch. The
Ignition Switch is in turn responsible for removing power from large parts of the vehicle on demand using the key. (Radio, fans, ignition, computer, etc)

So let's pull all this theory together via the 'total power loss after attempted cranking':


OK. We start off with the entire vehicle electrically operational. When the key is turned to START,
an initial rush of current is drawn. But due to a marginal connection at the battery, this sudden high current
flow opens the path that was supporting all the smaller electrical loads, and like the old camera flashbulbs,
somewhere was a bright flash, localized heat, and then exactly nothing. ALL POWER TO THE VEHICLE IS LOST.

EDIT: This isn't a bad starter solenoid, for that would only affect the circuits fed by the IGN A fuse. And it isn't a bad
Neutral Safety Switch or the control side of the Starter Relay, because that would only affect the CRANK fuse.
And it isn't a starter drawing more current than the battery can supply, for that symptom is the headlights
dimming excessively while cranking, but the headlights/dome lights, etc returning to near normal brightness once
the cranking is stopped.

Another item off the suspect list is the Ignition Switch, for when this specific failure happens, not only are the ignition switch-related
loads dead, but also all the other "Hot Always" circuits upstream of the Ignition Switch are also dead. (!)

The telltale, especially when troubleshooting a sudden complete loss of power (and it's impossible to completely drain a
fully-charged lead/acid battery immediately) is to turn the headlights on and then attempt to crank the engine. IF the headlights
stay bright while you are attempting to crank the engine, then we have an open circuit that only affects the cranking function.

But if the headlights suddenly go dead, plus you get no response from turning the key to START, then we are currently
experiencing an electrical circuit open in a spot where ALL the circuits have suddenly lost power.

****

This can and does happen to both conventional post and side terminal batteries, but assuming that you are running
the stock side post terminals in your vehicle, I can explain what happens the majority of the time. It seems that
there can be a tolerance stackup, where the factory cable bolts (with the 8mm head) are too long and bottoms out inside
the threaded battery hole *before* a solid electrical connection is made with the cable. I've seen it where I'm
close to stripping the soft lead threads in the battery, and yet I can still twist the cables side to side?

Sometimes this is due to the cable ends compressing just a bit, while other times the problem shows up coincident
with a new battery swapped into the engine bay. (And the new battery bolt hole(s) are too shallow for the stock bolt.)
And of course there's always improper bolt substitution over the years by some unknown mechanic who grabbed
whatever was in the used bolt bucket at the time.

For what it's worth, here's a thread where the owner was performing an engine swap, and suddenly he was also
experiencing a global loss of power immediately after attempting to crank over a recently installed 5.7. Here's
the reply where he finally troubleshot it down to the problem part: (bad battery bolt, clean but still no joy)

In addition to bottoming out due to a battery manufacturer getting the depth wrong or the starter cable
compressing a bit, the factory bolt design forces me to tighten into soft lead while simultaneously trying to get
a secure electrical cable connection. There are now 2 possible upgrades to avoid these issues:

1)

You must be registered for see images attach

This is a divide and conquer solution. You first torque this into the battery using the factory spec. (So you don't pull the lead threads.)

Now you can put a large wrench on this brass stud and keep it from turning while you tighten up the power cables
with the smaller fine-threaded nut. (As a side benefit, this also makes it easy to attach jumper cables if need be
down the road.) With my battery set up with a pair of these, I get a solid connection at the battery and I can
tighten my power cables until they are 'can't fail in flight' tight *without* overstressing the lead threads in the batteries.

Better than new...and that doesn't happen very often.

2) The other solution is using a longer bolt plus a nut. You siimply thread the bolt in gently until it stops,
and then use the nut to apply the necessary clamping force onto the power cables. Similar to replacing
head bolts with studs and nuts on cylinder heads. Schurkey demonstrates this in reply #91 to the other
thread mentioned previously. (Bolt & nut setup for battery cable connections)

****

That's all I got. The symptoms of a global electrical power loss after attempted high-current draw points
us to a connection issue right at the battery. (Or of course where the main ground connections are.)
This same global power loss allows us to remove the Ignition Switch and other non-global connections
from the suspect list.

And we also have a simple better than new solution to help resolve the problem, and more importantly,
prevent it from re-occurring.

Best of luck. And please reply back with what you discover to be the root cause/final fix.

Somewhere in that impressive data dump reply you nailed it. I had installed an aftermarket battery bolt for the 4 hi mod and future sound system. Even though the threads look identical, the bolt stripped. It would not stay tight and after enough arcs the metal tarnished enough to break the connection. I put the factory bolt back in and and it started right up. Will have to research better options going forward.

 

[Beason]

Thanks again to everyone who replied with suggestions. hopefully they help others in the future.