tbb2

2 years 7 months after the first time it happened ... no start, no lights, no nothing.
That is 2 years 7 months on an Interstate MT-78, 5 year battery.
Hooked up a 2 Amp charger to the battery and it barely budging the needle on the charger up off zero Amps.

I disconnect the battery overnight.
The next day the engine starts and then stalls when put in gear.
I start the engine and let it warm up and it does not stall out when in gear.
I drive several miles to see what I can note and everything works "normally".
The battery gauge reads 14 Amps which is "normal".

Checking for parasitic drain I find a 0.73 mA draw with everything shut down and door closed.
This being the same as when the blower motor resistor assembly failed.
I disconnected the blower motor resistor assembly and it did not change the draw on the battery.

I did parasitic drain test pulling every fuse in the under hood box.
None of the circuits changed the parasitic draw.
(?)
I also did a sloppy test, with the driver's door open, for all the fuses under the drivers seat.
I assume if one was implicated the 0.73 mA would increase.
(?)

Other than repeating the parasitic drain testing, could the drain be through something else?

mountainmanjoe

Your gauge indicates Volts, not Amps.

I doubt that your meter is able to measure micro-amps.
I think you mean 0.73 Amps, which is the same as 730 milliAmps

try unhooking the alternator.

Have the battery tested.
Other than that, it could be related to the rodent problem you had.

tbb2

Your gauge indicates Volts, not Amps.
-- My bad. Yes Volts.

I doubt that your meter is able to measure micro-amps.
-- mA milliamps; μA microamps
I think you mean 0.73 Amps, which is the same as 730 milliAmps
-- It is 0.73 mA, 0.069 A

None of the circuits changed the parasitic draw.
try unhooking the alternator.
-- Do you think the alternator is the source of the drain?

Other than repeating the parasitic drain testing, could the drain be through something else?
Have the battery tested.
-- The battery is weak due to the drain.
Other than that, it could be related to the rodent problem you had.
-- Are you referring to the post I did years ago on a battery cover?

mountainmanjoe

I think you are confusing metric prefixes
0.069 A = 69 mA

0.73 mA = 730 μA
which is basically nothing, and most handheld meters do not have this kind of resolution


Show a photo of your meter screen




I don't know. You need to unhook it and find out. I've seen it before.



By testing I mean checking the health of the battery, not measuring its state of charge. (eg dead cells, etc.)
Put it on a charger and then take it to get tested. Its free at the parts store.

tbb2

I see your point. The math does not make sense. I did the measurements again.
Red clipped to Negative cable Black held to rear battery socket.

See next two Amp, mA, photos?



I went back to get the uA measurement too.
See the different AMP and uA, photos?




Now I'm visiting crazy town since the Amp reading changed, AND the math still does not work.
I have to figure out how to test my meter.

AND you are also correct in that a 0.74 mA draw is low. In my bad memory, 0.50 mA was the limit and looking back it is 50 mA.

I used a different Multi-Meter and between the Negative cable and the Negative socket I got:
12.43 v
1 Amp (1000 mA)!
0 mA (the max is 200 mA so it would be off the scale)

Now I'm just confused.
I did have the battery tested and was told it was "good". Though the print-out shows it is just below spec.
I assumed a parasitic drain but with a now questionable MM.
With a different meter I am way over 50 mA at 1000 mA (1 Amp). At 1 Amp neither MM is going to read mA that high.

Would I now, using the second MM, do the parasitic drain test again using the 10 Amp setting.
- Now that I am losing my mind ... can I assume that if the reading is less than 1 Amp I will get fractions?
Later, sort out the 1st multi-meter.

mountainmanjoe

0.74 mA is absolutely expected, as is 0.006 A (6 mA)

0.061 A (61 mA) is a little high, but would still take weeks to run down a battery


The mA range is more sensitive than the 10A range.

tbb2

I think I sorted out the multi-meter by replacing batteries and fuses.
Drain:
0.640 mA
0.007 A ... rounding up from 0.00064 Amp(?)
So still too small to be the issue at hand though the battery is slowly losing voltage.
- 12.38 v down from 12.48 v just sitting w/ neg cable disconnected.

I think parasitic drain is off the table and I need to look elsewhere.
- A bad ground connection is on my radar though I have not figured out the how-to yet.
-- I just have not noticed any systems not working or being wonky due to being improperly grounded. (?)

The van still starts.
- Weak start ... starts to stall when gas pedal is ’touched’ ... starts to stall when returning to idle after gas pedal is punched.
- Engine has to reach warm-up temperature to idle normally with gas pedal applied and when put in gear.

This really 'feels' like a weak spark, as the battery is getting charged up by the alternator.
I did test the alternator as the van was started. From 12v dropping to 9v when cranking and then up to 14v when engine started.
So despite the garage's assessment that the battery is 'good' I am gong to replace it.

Has anyone seen a rear post battery disconnect switch?

mountainmanjoe

0.00064 Amp rounds up to 0.0007 A (0.7mA)
0.007 A = 7 mA (10x more)

Like I said, handheld meters are not very accurate down into the sub-1mA range. They usually have around 1% precision, and effects like burden voltage start to come into play.

Yes. It seems you don't have a parasitic drain


A healthy, fully charged battery should sit at about 12.6 to 12.7V
So it's low but should still start the engine.
How old is it?
Worn out batteries can develop shorts inside between the plates.
The only reliable way to test them is with a carbon pile tester. I'm sure your local battery dealer has one.

certainly a possibility. You can use your meter in resistance range to measure between the battery post and the engine block. between the battery and body/frame. between engine block and body/frame. Bad connections on the positive side are also possible Make sure ALL connections are clean and tight.



If the starter cranks normally then the battery is fine.



Poor idle is usually engine problem, like vacuum leak , dirty throttle body, or weak fuel pump. Especially if touching the accelerator pedal makes it worse.

Yeah it shouldn't be dropping to 9V. Engine should run normally with 14V though.


sure but I wouldn't bother complicating things.

dberladyn

I think that would just be the clock in the radio, the BCM and the ECM. Normal I would suspect.

This might be a stupid question, but as far as "drain" goes,... did you have a phone, tablet, etc. plugged in? I had horrendous problems that I couldn't solve for the life of me back in 2016. I was (wrongfully) thrown out of my home, trying to survive with a collapsing livelihood, finances, and legal affairs,... all while my brand new truck would just die. It just ate through battery charges / batteries.

Of course my head was a mess. It was impossible to fix anything in my life as no matter which direction that I concentrated within, a problem from another area of my life would suddenly impede headway. I am sure you can imagine trying to survive against overwhelming odds, only to have your truck continually die on top of everything.

My problem never truly went away until I added additional batteries.

Whatever the source of my problems, I think it was probably multiple. I was making changes to the truck, adding radios / computer / amplifiers. My truck was constantly a work in progress. I would use my truck to charge my phone and tablet. Looking back, I think my issues came from multiple sources and one of them was likely not realizing how much drain my phone was on the battery.

I am pretty familiar with my van's electrical schematics now, and I no longer have issues that way.