Harvard wrote: Are you sure, 3.51 Amps would kill your chassis battery within 24 hours....the 0.83 volts and 3.51 amps do not equate to one another if you are measuring across the open knife switch with the ignition OFF. It just does not add up....maybe 3.51 milliAmps but that still does not fit the 0.83 volts.
I had the "electro tek" meter set on 10 amp setting and yes it drains the batteries in about 1 to 2 days,....if the engine is not running I open the switch.....????????????????????????
does this sound like a direct short? there is no sparking when I close the switch.......
The fact that it kills your battery is crucial information for us, thanks for that. No, it is not a direct short, it is something drawing a lite load like a single light bulb (but not as much as head lights). Do you happen to have anything plugged into your OBD II port? I have a OBD II reader that will do this to me if I forget to unplug it, but my OBD thingy takes 4-5 days to kill the battery.
Also, just to confirm, you are using a different + plug on the DVM for 10 Amps, right? It is not the same + plug for Volts as it is for 10 Amps, are we on track with that?
A potential theory to justify the two readings of 3.51A and 0.83V! The theory would be that it (the problem load) is a solid state load (not a light bulb) that would drop the 12.6 - 0.83 = 11.77V without conducting high current because of the extremely small current allowed by the in series 10 MegOhms of the DVM 20 volt range.
Harvard wrote: Are you sure, 3.51 Amps would kill your chassis battery within 24 hours....the 0.83 volts and 3.51 amps do not equate to one another if you are measuring across the open knife switch with the ignition OFF. It just does not add up....maybe 3.51 milliAmps but that still does not fit the 0.83 volts.
I had the "electro tek" meter set on 10 amp setting and yes it drains the batteries in about 1 to 2 days,....if the engine is not running I open the switch.....????????????????????????
does this sound like a direct short? there is no sparking when I close the switch.......
The fact that it kills your battery is crucial information for us, thanks for that. No, it is not a direct short, it is something drawing a lite load like a single light bulb (but not as much as head lights). Do you happen to have anything plugged into your OBD II port? I have a OBD II reader that will do this to me if I forget to unplug it, but my OBD thingy takes 4-5 days to kill the battery.
Also, just to confirm, you are using a different + plug on the DVM for 10 Amps, right? It is not the same + plug for Volts as it is for 10 Amps, are we on track with that?
Yea.... I connected to the 10A port on the meter....I will start pulling fuses this weekend to solve this mystery......
When you start pulling fuses, insert your meter ( configured for the 10 Amp range ) in place of the pulled fuse. Find the one with the current draw you've found the circuit with the problem. If you have a wiring diagram look for the loads on that leg - you might see right off what is pulling the current or you would want to start disconnecting devices one at a time off that leg to stop the draw. You might find it to be a combination of devices - that's ~42W load. When we first got our coach I had a similar problem - it turned out to be the light in the "safe" was on all the time ( this is a small compartment under the passengers seat - door closed you could not tell ) - smaller draw than yours though.
Let us know -
1987 36' Beaver Marquis High Tech Wide body
3208T CAT, MT643 Allison in a Gillig MHA
Koni's & Toyo all around
FMCA, Good Sam
Since this is the chassis battery, do you happen to have an inverter plugged into a "cigarette lighter" socket that runs off the chassis? And yea, you got to let us know how this resolves, you got a bunch of folks scratching their heads on this one.
Just more generalized problem solving. One, did this coincide with the installation or repair of any electronic widget. Perhaps a new Navigation system?
Has it always been this way, and you have decided to fix it? Or did the start of this problem coincide with any specific event?
Richard, Rhonda, Ty, and Alex
1995 Newell with 470HP Detroit Diesel
Pulling 2002 Honda CRV with Alexis Towbar
Bikeboy57 wrote: Just more generalized problem solving. One, did this coincide with the installation or repair of any electronic widget. Perhaps a new Navigation system?
Has it always been this way, and you have decided to fix it? Or did the start of this problem coincide with any specific event?
It seems I have always had a chassis problem, I have the "duvac" charging system on my coach...in short I had a bad 12v sense wire going to the alt. this made the alt bounce while charging....I just discovered my converter (6345 magnetek) is not charging my coach batteries (installing a xantrex XADC 80amp on sat) but the (chassis)has been discharging for many months (if I forget to throw knife switch) hopefully this weekend I will have a update.......if I find a solution, no matter how dumb it makes me look... I will post it...LOL....jim
When the battery is charged, does the engine start ok?
I thought I had a faulty battery and I had similar conflicting voltage readings on my motorhome's chassis battery negative terminal. I thought it was caused by the nearby radio station's signal getting into my digital meter. As it turns out, the meter was accurate, but I sure was pulling my hear out for awhile. The problem was the negative lead connection at the frame.
The battery was not actually discharging or dead; I just thought it was. My "battery control center" has a problem that sometimes keeps the chassis and coach batteries connected even with the engine off and shore power not connected. So my voltage reading of something like 0.6 volts read between battery negative terminal and chassis ground (with negative terminal disconnected from battery) was actually the voltage difference between the 2 batteries.
(With negative terminal connected, voltage reading between negative terminal and a known good chassis ground did read a voltage, due to the voltage drop across the bad connection caused by a small current parasitic drain.
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