Mystery Volts
Hello everyone...
First time poster, but have lurked around for a while. I am hoping some of you folks might have an answer to my mystery. I have a 1988 Jayco and have been trying to track down a power issue. Namely my batteries are not charging. In the process of chasing this issue down I removed the batteries and had them recharged and check for good. They are Blue Top Optima Marines and they all charge and check good. I measured the power coming off of the truck and I am getting about 14.5V at the battery terminals with the truck running. So it seems that I have good batteries and good power coming from the truck. So I have begun to think about parasitic draw. Now the mystery. In my testing of the power coming from the truck I noticed that when I had the truck running I had a consistent 14.5V. However, when I turned the engine off the volt meter did not go to zero, like I expected. Instead it began decreasing the voltage measurement on the meter like it was "counting down". I thought that maybe something might be still on in the truck side of things, so I disconnected the uncial from the truck, with no change in the voltage reading on the meter, it still continued to "count down". Please keep in mind that I have no batteries in the camper currently, so I am confused as to where the reading is coming from. If I started the truck the voltage would go back to 14.5 and when I turned the truck off it would "count down" again. I turned off all of the breakers in the electrical panel with no change in the behavior. I do have three small 12V fuses, so I pulled each one at a time and found one that will change the voltage reading to zero. If I put the fuse back in the voltage goes right back to "counting down", pull it it goes to zero. I have no idea what the fuse is to. So my question is. Can anyone tell me why this happens? The truck's umbilical is disconnected and there are no batteries installed and no shore tie, why can I still read voltage with seemingly no power source?I find myself wondering if this might be the cause of my batteries not charging. Any ideas would be greatly appreciated
First time poster, but have lurked around for a while. I am hoping some of you folks might have an answer to my mystery. I have a 1988 Jayco and have been trying to track down a power issue. Namely my batteries are not charging. In the process of chasing this issue down I removed the batteries and had them recharged and check for good. They are Blue Top Optima Marines and they all charge and check good. I measured the power coming off of the truck and I am getting about 14.5V at the battery terminals with the truck running. So it seems that I have good batteries and good power coming from the truck. So I have begun to think about parasitic draw. Now the mystery. In my testing of the power coming from the truck I noticed that when I had the truck running I had a consistent 14.5V. However, when I turned the engine off the volt meter did not go to zero, like I expected. Instead it began decreasing the voltage measurement on the meter like it was "counting down". I thought that maybe something might be still on in the truck side of things, so I disconnected the uncial from the truck, with no change in the voltage reading on the meter, it still continued to "count down". Please keep in mind that I have no batteries in the camper currently, so I am confused as to where the reading is coming from. If I started the truck the voltage would go back to 14.5 and when I turned the truck off it would "count down" again. I turned off all of the breakers in the electrical panel with no change in the behavior. I do have three small 12V fuses, so I pulled each one at a time and found one that will change the voltage reading to zero. If I put the fuse back in the voltage goes right back to "counting down", pull it it goes to zero. I have no idea what the fuse is to. So my question is. Can anyone tell me why this happens? The truck's umbilical is disconnected and there are no batteries installed and no shore tie, why can I still read voltage with seemingly no power source?I find myself wondering if this might be the cause of my batteries not charging. Any ideas would be greatly appreciated
