18 days into a 3 week holiday, things were mostly well until this morning, sigh, here we go again....Parked the truck at the campsite day before yesterday afternoon. Didn't run it yesterday. Went to head out this morning and the truck wouldn't start, batteries were dead. Enough juice to make the solenoid click a bit, that's all.What the heck? Feb 4 this year, 2 new batteries, March 8, new alternator.When I tried to start it I had a weird smell come out the AC/heat ducts. Not quite a burnt electrical smell but similar.I'm baffled here. Thing was running fine until this.Pulled the negative terminals, put on an ammeter, looked at readout. Started at 1.67A, bled down to about .11A and stayed there. Left the batteries disconnected for about 7-8 minutes, hooked them up and ran jumper cables to my TT house batteries. Gave it a couple hours for the converter to charge them a bit.Got it started, ran it a few minutes, alternator got hot rather fast, but it's working so I get that.Took it for a run for about a half hour, seems to be ok now. Except that weird smell...It's been a couple hours shut off now, going to go back out, pull the negs and do the ammeter test again.My question regarding all this:What is the nominal draw in amps that should I be reading? That is, the normal amount of parasitic drain? Milliamps I guess, not amps.(TV in sig)

Brain lapse...Think I'm reading my multimeter wrong.I set it to DC mA. On the 30 setting of the dial it settles to .1mA

Did you power the converter from shore power or from a generator? reason to ask is:If you are off grid, and you leave the 7-pin connected while parked engine off, your Chev will be "live" with the engine battery in parallel with the trailer batteries. So that could be good or bad for the truck battery depending on whether the trailer batteries are being recharged or run down.Generally with a Chev, disconnect the 7-pin when you are parked for very long.

start the truck take it for a drive, run every single accessory you can.shut it down disconnect battery put meter inline and wait 15 minutes, it should drop,remember most meters are fused at 500ma or lower for the Ma rating, if u saw 2 amps and tested it on the ma setting you prolly blew the fuse. check the fusenormal ma draw is somewhere in the area of 30-40ma. you should let the vehicle sit over night and check it in the morning as well, with not opening the doors or touching anything that will power the computers back up. that said a 100ma if that is remotely accurate should not even come close to draining 2 batteries in 1 day

BFL13 wrote:Did you power the converter from shore power or from a generator? reason to ask is:...snipFull hookups, truck is disconnected.

LittleBill, My ammeter says 10A max.I ran it there initially for the reading in my first post, just to be sure I didn't blow something.Once I saw it wasn't drawing a huge amount I set it to mA on the 30 range of the dial. It began at around 70 and settled down to .1 mA after about 30 seconds. Held it there for about 1.5 minutes and it stayed there.

Batteries drained to dead, what is nominal drain on truck?

BobsYourUncle
Nomad
Aug 22, 2019
joebedford wrote:
If you're using the truck's wifi, that will flatten the battery overnight. Ask me how I know (twice).

Trucks wifi? Not in 2007! :)
BobsYourUncle
Nomad
Aug 22, 2019
Unhooked the batteries for a couple hours.
Hooked them back up again after running the ammeter test again, guess I'll find out tomorrow if it was a gremlin that visited or if the issue is still there. Hope it doesn't persist, I have about a 9 hour drive to get home on Sunday...
JiminDenver
Explorer II
Aug 22, 2019
Bob, get a DC clamp meter. So much easier.

I wonder if the smell is a a ventilation door actuator that gets stuck on and resets itself once the battery goes dead. I would not think it would happen with the key off but who knows. It certainly sounds like a electrical part is hot but not burning.
jkwilson
Explorer II
Aug 22, 2019
Have you checked electrolyte levels?
joebedford
Nomad II
Aug 22, 2019
BobsYourUncle wrote:
joebedford wrote:
If you're using the truck's wifi, that will flatten the battery overnight. Ask me how I know (twice).

Trucks wifi? Not in 2007! :)
Sorry. Mine's a 2011. And the wifi was a free retrofit when they dropped 2G coverage in Canada.
BobsYourUncle
Nomad
Aug 22, 2019
JiminDenver wrote:
Bob, get a DC clamp meter. So much easier.

I wonder if the smell is a a ventilation door actuator that gets stuck on and resets itself once the battery goes dead. I would not think it would happen with the key off but who knows. It certainly sounds like a electrical part is hot but not burning.

Yes, the DC clamp meter. It was actually on my list of things to buy before leaving on the trip. Never did get it, so had to use my old multimeter..

Agree with the something got hot. Trying to determine what is the hard part. Something stuck on, causing a hard drain on the batteries. Smell in the AC vents is the only clue I have.
Years ago I had the cab fill up with a similar smell and smoke. So bad I actually pulled over on the highway and bailed, thinking I was on fire. Turned out to be the fan speed control on the heater box. Apparently there was a recall on it years ago. I put a new one on and all was well.

I've checked everything, it all works.
theoldwizard1
Explorer II
Aug 22, 2019
BobsYourUncle wrote:
Pulled the negative terminals, put on an ammeter, looked at readout. Started at 1.67A, bled down to about .11A and stayed there.

Under 250mA (0.25A) is typical. As you said, it might take 5 minutes for all of the electronics to go to sleep.

Some electronics occasionally (once every 10 to 60 minutes) "wake up" to check things, but they go back to sleep.
theoldwizard1
Explorer II
Aug 22, 2019
JiminDenver wrote:
Bob, get a DC clamp meter. So much easier.

Clamp meters are not always accurate below 1A. Not sure if 0.1A (100mA) would register on some.
steved28
Explorer
Aug 22, 2019
theoldwizard1 wrote:
JiminDenver wrote:
Bob, get a DC clamp meter. So much easier.

Clamp meters are not always accurate below 1A. Not sure if 0.1A (100mA) would register on some.

Still, should be standard equipment for every RV'er who knows about current. I use mine all the time.
BobsYourUncle
Nomad
Aug 22, 2019
Thanks for the help guys. :)
Truck seems ok at the moment.
Drove around today with multiple start stops.
Long as I can get it home Sunday without it happening again.
Easier to do the slow painful trial and error find the culprit process at home where I have access to all my tools and such.

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Batteries drained to dead, what is nominal drain on truck?

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