Batteries Discharging everything off. ?¿?

[COBB]

I Dont get it ,Nothing but Electrical , since day 1

No matter how hard I try Batteries wont stay charged, everything appears to be off,if i stsrt it every hour its great if i wait say 3 hrz. Forget it to low to even engage starter.

Any idea how i can track down somthing using power with no sign of anything being on .
Please any ideas are welcome



Tha ks ,,.. SCOTT

[TheHubbardBus]

I don't know where the similarities begin or end between manufacturers or model years. But our 2003 IC has two fuse boxes, one of which is for the body, and one of the 4 columns on this body fuse box is for 'always on' circuits. If something on one of those always-on circuits was drawing power, it might be one (but not the only) way you could be running down the battery. To diagnose, you have a few options. If you have a multimeter or ammeter, you could measure current across the the back of each fuse (with the fuses in place, and the key off). If you get a reading, that may be your pony. Pull that fuse & see if the problem goes away. If you don't have a multi-meter, you could just pull all the fuses, and if the problem goes away, add them one at a time until you have the problem again. But that's really time consuming. If I didn't own one I'd buy one. Doesn't have to be an expensive one and they have countless uses.

[flattracker]

Some suggestions:
Disconnect the negative terminal on all of the batteries. (negative disconnect is safer since it is at ground level)
Charge the batteries to full charge. After overnight disconnected, check battery voltage, and if low (below 12.5 volts) replace one or both.
If batteries are good or replaced, connect one and check current flow with all turned off. Harbor freight sells a DC clip-on ammeter that can do this, alternate go to eBay.
If there is current flow, disconnect the wire going from the alternator to the batteries. Check for current flow again.
If current flow stops, replace or rebuild the alternator. If the diodes in the alternator fail the alternator can pull current from the batteries.
If there is still current flow after testing / replacing alternator, disconnect the positive connection at the starter switch. Check for current flow. Given the year of your bus, you probably have computer(s) that control the engine. I would look there next.


I invite others to elaborate on that part.



I had an 82 Firebird that would kill the battery over the weekend due to a failed engine computer.

[HamSkoolie]

No need to go to flea bay. Hit Harbor Freight, Lowes, Home Depot and buy a multimeter. You NEED ONE.


Charge your batteries to full charge with ground disconnected.
Let sit at least four hours after charge and check voltage.
Use YouTube university to determine if batteries are or probably are bad.


If suspect, take them to a battery store for testing.


If not suspect......use YouTube university to learn how to diagnose a PARASITIC DRAW and find that draw.

[magnakansas]

Here is how I am going to call this one.

Your batteries are toast. because

you have a smallish current draw and the batteries have been pulled down to high discharge too many times.

The cable connections to the batteries, are not is super good shape.

and just maybe there are problems with the cables to chassis, frame and engine grounds.

I bet you dont have one problem. you have three or four and they finally added up to a problem big enough that the system is not able to function.

You dont have a battery problem, you have a system problem and should check the health of the entire system. dont stop check when it works again. stop checking after you have checked the entire system.


william

[rossvtaylor]

As mentioned, you need a meter. Get one that has a clamp-on DC current function, so you can clamp it around a battery lead and see if current is flowing...discharging the batteries.

Then, get your batteries load tested. That's the only way to know if they're good or not. This video is for starting batteries, but the lesson is the same. Voltage doesn't tell you if a battery is good or not. In fact, we recently bought a truck that had two batteries and one had a bad cell in it. That shorted cell not only killed that battery (or, more properly, was a symptom of a killed battery)...but it also sucked down the other battery which was in parallel. https://youtu.be/ystmn3ly61Q

[HamSkoolie]

Actually, a meter can tell you if you have a bad battery....but not ALWAYS. If, after charging, you have less than 12 volts for instance, you definitely have a bad battery.
It can't tell you you have a good battery, that's a load test.

[Oldyeller]

Do what HamSkoolie said.

I bought a collector car which seemed to have something pulling down the battery. I skooled myself on YouTube about doing a parasitic draw test and then performed it on the car. In my case it turned out that my draw was 'by the book' but being able to confirm it was helpful.