Please help me diagnose my electrical issue...

Everywhere I use a multimeter or a test light it all checks out... This morning I woke up and went to turn the generator off (the fridge doesn't seem to want to work on shore power so I run the gen overnight)... It wouldn't shut off! I had to hook up my battery charger to the batteries to be able to shut the generator off. The generator is diesel by the way. So now my batteries don't charge with the generator, the fridge works with the generator running, the shore power will not run the fridge. I'm still not quite awake yet so ask away please.

I forgot to add that it's a 50 amp system.

It sounds like a problem with the transfer switch. It woulds help if you were to tell us just what tests you've done with your multimeter.

Joel

Well, none of that makes any sense, so we will have plenty of questions.

The first question concerns shore power and the auto transfer switch (ATS). The ATS switches the power source from shore to genset and defaults to genset, so I'm guessing yours isn't working.  When on shore power, check to see if anything in the coach has 120v power, e.g. any wall outlet, microwave, etc. If none have power, odds are the transfer switch isn't transferring.


Does your coach have a separate battery for the genset?  They often did back in the 90's, but later years use the house or chassis battery to start & run the genset.  Which battery did you hook the charger to and get it to stop?

You also state the battery (house or chassis?) doesn't charge with genset running. What about on shore power?  How did you determine this, e.g. with a voltmeter, or some gauge or light in the coach, or  ??  With neither genset nor shore active, do you have lighting in the coach?  That is 12v power and comes from the house batteries if no other source is available.

Gary RV_Wizard said:

Well, none of that makes any sense, so we will have plenty of questions.

The first question concerns shore power and the auto transfer switch (ATS). The ATS switches the power source from shore to genset and defaults to genset, so I'm guessing yours isn't working.  When on shore power, check to see if anything in the coach has 120v power, e.g. any wall outlet, microwave, etc. If none have power, odds are the transfer switch isn't transferring.

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I will double check that, I can hear it switching from in the coach and I also have the panel off, hit the switch on the one that was off and it switched back right away. So it is switching, but I will check it out again.

Gary RV_Wizard said:

Does your coach have a separate battery for the genset?  They often did back in the 90's, but later years use the house or chassis battery to start & run the genset.  Which battery did you hook the charger to and get it to stop?

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I bought the MH almost 3 years ago and it only had one battery in it for me to drive it home. I have 2 batteries and everything is connected to them.

Gary RV_Wizard said:

You also state the battery (house or chassis?) doesn't charge with genset running. What about on shore power?  How did you determine this, e.g. with a voltmeter, or some gauge or light in the coach, or  ??  With neither genset nor shore active, do you have lighting in the coach?  That is 12v power and comes from the house batteries if no other source is available.

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I assume the genset isn't charging the batteries since I had it running all night and once I shut it off, it won't start because the batteries are dead. That said, I have been having trouble determining if the battery switching is actually occurring, maybe it won't charge the batteries if the switch isn't on?

"Normally" the genset does not charge anything, it produces 120V which is then used to run the converter and that charges the house battery (ies) just as it does when plugged in. Note that in some cases, the batteries may not charge if the battery store switch is in use (in the store position). Not all coaches are arranged that way but some are.

Great Horned Owl said:

It sounds like a problem with the transfer switch. It woulds help if you were to tell us just what tests you've done with your multimeter.

Joel

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I will have to go over it again, or at least reply when I am at the MH.

You should have at least two separate 12v power systems in the coach (3 if the genset had its own).  Originally, you would have had two 12v batteries to start the diesel engine, and 2-4 more to provide power to the house (lighting and such) when neither shore power nor genset was in use.  The genset starts off either house or chassis battery (usually chassis) if it doesn't have its own battery.  Clearly yours has been modified, so hard to guess how things are wired now.

The coach was originally equipped with a 40A converter/charger (75A optional) that provides 12v to the house and charges the house batteries when either shore or genset power is in use. The genset does not directly charge house or chassis batteries - it merely provides 120v power to the converter/charger. 

Normally there is an isolator to keep the chassis and house 12v system separate, the idea being that you can run the house system down to "dead" and the engine can still be started via its own battery. Apparently yours no longer is isolated.  If you have only two batteries, it sounds like both hose and chassis are combined.

You mentioned a battery switch of some sort. Typically there is a battery disconnect which take the house batteries offline. Sometimes one for the main chassis battery as well.  Neither battery will charge if that switch is off - nothing is connected to the battery in that case, so no path for charging.

Everywhere I use a multimeter or a test light it all checks out...

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Could you elaborate on what you checked and the results? House 12v system, Chassis 12v system,  and/or 120vac system?

the fridge works with the generator running, the shore power will not run the fridge.

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Is the fridge running on LP (propane) or 120v electric?  In the electric mode, the fridge doesn't know whether the power came from genset or shore, so it cannot matter except back at the transfer switch where the source is selected.  HOWEVER, the fridge also needs 12vdc whether in gas or electric mode.  If somehow you have no 12v power when using shore instead of genset, then the fridge would not work. Nor would some other appliances and the interior lighting, so that should be pretty obvious.

You may find some helpful info in this 1996 Newmar brochure. It covers both Kountry Star and Dutch Star, and Dutch Stars came in btg gasoline and diesel models back then, so be careful to read only the sections that apply to  your coach.

https://newmarcorp-8c1e.kxcdn.com/wp-content/uploads/pdf-archive/1996-kountry-star-diesel-pusher.pdf

What concerns me is he had to hook up a battery charger to get his generator to shut off.

Both the Fridge and the Generator need 12 volts to run if the batteries were that low that the control line to the Generator would not shut it down..... Something is fishy in the 12 volt system.  I would look there before I dug into the 120 volt too deeply. THOUGH. a bad ATS can also cause a "no charge" on the batteires.

But the Generator needs 12 volts for hte fuel pump (At least gassers do) and the fridge for control in most cases.  When my convertetr died ther FRIDGE was the indicator. IT quit.

He might need 12 volts to operate a solenoid valve to shut off the fuel to the generator. If that was the case, the solenoid operated when he hooked up the charger.

Closing a fuel solenoid IS how a diesel gets shut down, but there should be enough 12v while the diesel is running.  The only thing I can think of is that as it shut down, the 12v power was lost (converter/charger lost 120v power) and the solenoid opened, allowing the engine to start running again.  The fuel solenoid has to remain closed until the rpms go to zero.

But this raises the question of where did that auxiliary battery charger get 120v?  Plugged to shore power, maybe?
There are simply far too many gaps in the info available to reach any meaningful conclusions.

I agree. I was just kinda grasping at straws with my post. It sure is easier troubleshooting electric when you're right there with hand's on.

The battery charger I hooked up this morning is just a portable charger. And it was plugged to shore power to get enough voltage to shut genset down. Nothing that ran 12 volts would turn on, the batteries were drained. When I hit/held the shut off switch for the genset, it wouldn't respond at all until I hooked up the charger.

Please bare with me guys, I'm good with electrical but a lot of this confuses me.

Just like this... https://youtu.be/QH0jYnp0Zc4 https://youtu.be/WRthPHwbNlk

I've edited my post to include a couple of videos I took yesterday.

You need to start systematically doing basic checks with a multimeter to determine what is happening (or not happening).  When things get really flaky like this, it's back to basics and step-by-step verification of the power path through the electrical system.  You have symptoms of both 120vac and 12vdc power problems, but it is possible the 12vdc is a side-effect of the 120v issue. 

One of my first steps would be to make sure the battery disconnect(s) are functional, cause most rigs can't charge the battery is the disconnect is in the Off (aka Storage) position.  If in doubt, jumper around the solenoid with a battery cable.  Another step is to determine if 120v power is reaching the load center and from there to the converter/charger, both on shore and genset power.  Then, if the converter/charger has input power, is it producing +12v (actually more like 13.3v) for both battery charging and house 12v usage. Measure voltage at key points to determine where the system is broken, then focus in from there.

I'm a little more prepared to tackle the issues this week, but last Tuesday or Wednesday night I hit the battery switch and this time it seemed to have activated the latching solenoid... Plus, all issues disappeared so I'm thinking it's the latching solenoid or the controller for it. I will install a bypass switch in the compartment in case it happens again.

Sounds like yu are on the right track.

On my coach the switch was dirty. I removed all power. cycled it like 50 times (There is a 5 amp fuse if you can ID It. I Disconnected the switch)

and it's worked ever since.

Hey there, sorry it took so long to update. It's been such a bad summer in my area, it was either too hot or rain, so I couldn't get to doing much testing. I still have to locate my short but I've found that the A/C plug that the fridge plugs into has now power, and the on-board battery charger had the same issue. I no longer have to use a portable charger and the fridge is working on A/C with an extension cord.

Lack of time and terrible weather just made it impossible to work on. That said, there is definitely a short to ground since I can get a mild shock on the compartment door frames on the left side of the coach.

Now it's about time to start getting her ready for winter, I will have to resume my diagnostics in the spring.

On a different note, my wife and I were quite relieved that the tornadoes that went through our area didn't damage the RV.