Electrical poblem at campground

[Fred Mc]

So I?m camping and the water pump stopped. The ground was bad so I fixed that. Happened again today and it?s not the ground. Only getting 11 volts to it started looking around and when I?m on house batteries I get 12.65 to the buss bar all the 12 volt stuff runs off but only 11 volts at the other end( lights, fridge,water pump etc) When I connect the house batteries to the start batteries everything works normal Also when I turn off house battery system and run everything off start batteries ONLY everything works fine.
I recently installed an inverter and used it today to set up my tv. Other than that no changes as it?s been working fine

I suspect a ground somewhere but can?t seem to figure it out and don?t want to run down the start batteries.

As a further followup both house batteries and start batteries use the same chassis ground

I have 3-12 volt start batteries and 2-12 volt house batteries.
Also when I use 110 volts everything works fine thru the converter
Any suggestions

Regards

Fred

[chessie4905]

You should test house batteries. You may have a weak one or two. A battery hydrometer will tell you by checking the specific gravity of electrolyte of each cell. Hydrometers are also cheap.

https://www.amazon.com/OTC-4619-Professional-Battery-Hydrometer/dp/B0050SFVHO

[richard5933]

Or possibly one of the battery cables on the house system is compromised? They can look good on the outside, but still have corrosion where the cable connects to the clamps/lugs. Check them carefully.

[Fred Mc]

Cables are all new as I just installed house system. Fortunately I have my hydrometer with me. Will check that out.

Thx

[Fred Mc]

Here is what I discovered so far. With devices that have a direct connection to positive and negative on battery like fridge and water pump  seem to work ok. For those that use chassis ground the voltage is severely reduced.

[eagle19952]

Here is what I discovered so far. With devices that have a direct connection to positive and negative on battery like fridge and water pump  seem to work ok. For those that use chassis ground the voltage is severely reduced.

well there you go.

[chessie4905]

Rusted bodies are not a good conductor of electricity. Do you have an older coach? Rust and corrosion can take a toll on all bodies, steel or aluminum, especially as they get older and spent time running in areas in winter where salt was used.
Your connection to the body for ground may not be a good connection. Try using a star washer between wire terminal and body with a coating of anti oxident or grease and recheck voltage. Make sure wire to wire terminal crimp is proper or soldered.

[richard5933]

This was a problem on our 4106, and I found many places where ground connections had to be re-made. The star washers do help, and so does a rub down with some emory cloth. There were some terminal strips being used inside the coach as a ground buss bar, and some of those had bad ground connections at the point they were joined to the chassis.

We also had problems in our current bus (4108) with grounding issues, some related to bad ground connections and some related to a totally different and strange issue. Not sure if this is what you're dealing with, but I discovered that for some reason Custom Coach took a wiring shortcut and used the neutral/ground of the 120v system to ground parts of the DC system. I discovered this when I turned the manual transfer switch to off and my LED lights suddenly started acting strangely. Turn the transfer switch to either shore or generator settings and everything was perfect.

My coach was wired with a bonded neutral & ground. (I know - it's a bad thing and we're working to remedy that situation. Topic for another conversation). The manual transfer switch switches both the hot and the neutral leads of the power source. When the switch was in the off position anything that was using the neutral/ground side for grounding was suddenly missing a ground. I separated out all the DC circuit ground wires that I could find and connected them directly to the chassis for a proper ground. This seemed to fix the problem for me.

Like I said, not sure if this is your problem. Just mentioning it to point out that there could be some strange things which were done to our buses before we got them, even if made by a professional team like Custom Coach.

[eagle19952]

Do you have an older Eagle?lol
this was funny once or twice.

The star washers do help, and so does a rub down with some emory cloth.
This was a problem on our 4106, and I found many places where ground connections had to be re-made.

[Fred Mc]

Well Richard, the only strange things done to my bus (4106 )have been done by me. 
So I spent most of the day trouble shooting (isn't that what your supposed to do when camping ) and ran separate grounds from battery to fridge, water pump and furnace so they worked fine. Lights, which are still grounded to chassis, still didn't work properly. Then suddenly last night EVERYTHING worked. Hmmmm.

[chessie4905]

Grounding to aluminum does cause issues over time from corrosion starting. They make a paste for household electrical that helps deal with  connections at the panel.
I use this, although mine is in a squishy bottle I bought years ago. I think Amazon and Lowes also sell it.

https://www.homedepot.com/p/Ideal-NOALOX-4-oz-Anti-Oxidant-Compound-30-026/202276208

[windtrader]

Would using a Electrical Contact Grease keep the conductivity intact longer and minimize the corrosion?

[Fred Mc]

My problem is that the spots where I would have attached grounds for lights has been covered by panels, cupboards,etc.

[silversport]

When I rewired my 4106, I ran all grounds back to the batteries using many grounding bars through out the coach.

[chessie4905]

The stuff works. It won't degrade or corrode once you use it.Sort of like anti-seize for electrical connections.