Hot Ground???

[buylow12]

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

[buylow12]

Yea, that would make sense, it is only maybe a foot from where the splice is. Do you mean like an in line fuse? I pulled the face plate off and didn't see anything like that. Additionally the wire is not of the same type as the splice.

Tim Czarkowski
Totaltravelers.com

[zach477]

Here's another idea. You said one of the 12v recepticles doesn't work. The mystery wire could be for that. The recepticle may be faulty or have some metal debri shorting it out causing the drain.

Does the 12v recepticle have a fuse you can pull?

[buylow12]

Your edit is correct. I think I'm only making it more confusing now, lol. To be clear the 10 amp draw was from a splice right before the fridge which has nothing to do with the panels or their controller.

Tim Czarkowski
TotalTravelers.com

[zach477]

buylow12 wrote:

Yea about that........... that was just my confusion on the fact that the negative and ground wire are the same thing. I was talking about another wire I pulled off the negative post because I was assuming it was the "negative cable". Now that I think about it, that might have been the panels 😉 Now I know, lol.


Tim Czarkowski
Totaltravelers.com

Just to clarify, the one that you think may come from the solar charger is the one that read 10 amps?

Edit* I just went back and read your earlier posts and it appears to be the other way around, correct?

[buylow12]

Yea, I know what he meant, I was just joking. If it was 10 amps going in from the panels(which run from the panels to the controller and then directly to the batteries) then pulling the fuse on the fridge would have almost no affect on the number, whether it was positive or negative. Instead it instantly drops to a normal amount(from 9.5 amps to 0.223 amps). I believe the solar controller won't allow current to flow the other way,but I assume a small amount must go to running the controller at night or in the shade. I can't imagine it's a whole lot.

Yea about that........... that was just my confusion on the fact that the negative and ground wire are the same thing. I was talking about another wire I pulled off the negative post because I was assuming it was the "negative cable". Now that I think about it, that might have been the panels 😉 Now I know, lol.

I still haven't found whatever it was that was disconnected. Is there a better way to hook those three cables up? At least I think it would need a larger nut, it was still a pretty tight fit with only two. It couldn't be a bid connection with three.

Tim Czarkowski
Totaltravelers.com

[zach477]

MrWizard wrote:
Hypotheses

IF the solar is wired to house wiring negative and NOT run all the way to the battery

using the meter lead to measure that circuit, would create a 'short cut to ground' and to the batteries, causing the meter to read ten amps

he will soon know if the solar charging is NOT working

I like it!

Tim, I'm curious....up until you started trying to daignose the problem, what was the LOWEST battery voltage you measured after heavy use? And what was the lowest you measured after just leaving it sit with no use other than your mysterious draining?

[MrWizard]

Hypotheses

IF the solar is wired to house wiring negative and NOT run all the way to the battery

using the meter lead to measure that circuit, would create a 'short cut to ground' and to the batteries, causing the meter to read ten amps

he will soon know if the solar charging is NOT working

[zach477]

Some solar systems can actually drain a battery at night or in the shade, oddly enough, but what I think BFL13 meant was maybe it was 10 amps going IN to your battery from the panels rather than 10 amps being pulled out of your battery. You said you have 200 watts of solar....10 amps almost sounds right...

I'm still confused as to why you get ten amps between the negative battery post and ground, but much less than that when you measure from the negative battery post to the end of the negative wire. The wire should connect to the frame (ground). What are you using for you ground point when measuring this? What's puzzling about this is that they should be the same.

[MrWizard]

i was under the impression that all fridges mounted in slide outs with vents in the wall had fans mounted near the fridge coils
there have certainly been a lot of posts, about the fridges not cooling correctly and the various causes

i would stick my head in there with a flashlight (if needed) and take a good look

[buylow12]

No, I hope the panels wouldn't drain my battery, that kind of defeats the purpose, lol.

It's probably confusing because I was confused myself when I wrote most of those posts 😉 That was the first time I worked with a 12v system and the first time I really used my multimeter.

Tim Czarkowski
Totaltravelers.com

[BFL13]

I got hopelessly confused reading this thread, but anyway.. 🙂

Any chance that almost 10amps draw is actually a plus instead of a minus (meter leads reversed) and is the solar charging?

[buylow12]

Trust me, I'd like to know what it is and will keep looking but I'm glad I don't have to worry about killing my new batteries anymore 😉

My fridge doesn't have a fan(as far as I know at least, lol). Trailer brakes and landing gear are both working fine, we just switched campgrounds earlier today. The fridge is in the passenger side slide so I imagine it would likely be something else in that slide usually, right? The only thing that isn't working over there is the 12v receptacle but that wasn't working before either and with nothing plugged into it, it shouldn't be pulling almost 10 amps.

Keep em' comin' 🙂

Tim Czarkowski
Totaltravelers.com

[MEXICOWANDERER]

A JOKE

Connect 120vac to the black wire and whatever smokes and catches fire is the culprit.



One Fruitwood Blunder, I had to re-wire for Good Sam had snarls of wire added on. I had to call the adjuster out and he took Polaroid images and told me to wait. They and the owner smoked the peace pipe and I was finally given the go ahead to fix it. "Someone" over rode (bridged) the neutral separation between shore power and generator and when the trace inverter was connected, and the rig was connected to reverse L1 and L0, all hell broke loose. I must have used thirty terminal blocks in the fix. I had informed Good Sam that wire nuts would be used "Over My Cold Lifeless Body" Not a hint of resistance from Good Sam. I rewire with 12-gauge receptacles wire. Red and yellow for interior lights and 12 volt battery feed. Black for 12-volt negative is for corpses waiting to happen. Black and white for L1 ID and Black with white tracer for L2.

[Salvo]

I would advise you to find out what you disconnected. It shouldn't be that difficult.

[MrWizard]

burned out fridge fan ?
trailer brakes ? (which should be connected at the 7 pin connector)
electric tongue jack for TT
landing gear for 5ver