Forum Discussion

buylow12's avatar
buylow12
Explorer
Aug 14, 2015

Hot Ground???

Alright, so after replacing my batteries I thought that our problems were solved. Especially when we arrived after two weeks to fully charged batteries in the storage yard(The refrigerator was hot however as it's fuse apparently blew :(. It was not to be. Again today when we arrived to the park our batteries were only reading 12.5v. I was thinking maybe it was the refrigerator doing something crazy since with the blown fuse our batteries were showing a amazingly full 13.2v at 2 am after two weeks on solar alone.

So I broke out the multi meter and tried to track down any leakage and I got a bit of a surprise. When I touched the negative post to the negative wire I only got .75 amps or so but when I touched my ground wire it was reading 10 amps. That was on top of a bit of sparking when I removed it. Can this be the cause of my battery drain?

I've got to admit I'm a bit confused at this point ;) From some reading I take it this is called a hot ground but I'm not sure what to do about it. I tried pulling all the fuses and putting them back in one by one but it seemed that anything that was on would increase the amps through the ground. How do I fix this?

Thanks(as usual) for the help,

Tim Czarkowski
TotatTravelers.Com
  • to me it sounds like your NEG-ground connection
    is NOT grounded at the frame, the wire is broke, or the fram connection corroded

    when you put the meter directly between negative and frame ground you supply a clean good path
    yes 10 amps is high for parasitic loads
    could be a bad control board on the fridge, or something else

    fix your neg to frame ground
    then track down you load
    i would pull the DC fuse for the fridge for a starter
    then the rest
  • I am using a panel from my solar controller. The 13.2 reading was at 2am after two weeks unplugged in a storage yard I assume the panels had brought it up to that point that day. Previously after a day of towing I'd get a reading of 14.4 which would then fall to a more normal 12.9 after being disconnected.

    Something is discharging my batteries. Even while towing or in the full sun on my 200w of solar the batteries are dropping. As I said I thought it was something with the fridge but testing with the multimeter made me think maybe it is something else. Am I correct in that the reading from negative terminal to ground should be 0 amp or very close to it? It seems weird to me that nothing would run without the ground and that there appears to be 10 amps running through it. Still confused :(

    Tim Czarkowski
    Totaltravelers.com
  • This is from my batteries, the 12v DC system. With the ground wire off all my 12v equipment stopped working. From the negative terminal to the ground with all the fuses in I was getting 10 amps or so. From negative terminal to negative wire I was getting 0.75 amps. This seems clearly wrong from what I have read and sounds like a hot ground. However I'm confused, as I said above. I just want to be able to boondock without watching my batteries rapidly discharge.

    Tim Czarkowski
    Totaltravelers.com
  • How are you testing the battery? A full battery should be 12.6 volts. 13.2 is a common voltage for a charger to be sending the battery.
  • Not sure I would be trouble shooting using current flow or ammeter setting. Especially since you mentioned blowing a fuse. A shorted appliance and using an ammeter can damage the meter. You can use the voltage scale and easily locate an open ground. If you have an open ground most likely problem is where it connects to the frame. Either at the battery end or the appliance end. Measure voltage across item in question. If no voltage move the negative probe to the battery terminal negative post. If you have voltage the ground is open. If the fridge worked before and blew a fuse could be a bad circuit board. If the fuse is blown I would remove the positive lead from that board, replace the fuse and measure the voltage. from the positive wire you removed and the ground on the board. If you measure 12 volts you have a problem with the board. In fact that is the test I would try first. Hope that makes sense.

About Technical Issues

Having RV issues? Connect with others who have been in your shoes.24,190 PostsLatest Activity: Jan 22, 2025