Total Electrical Failure After Starting Generator

[Just_Jeff]

Has anyone had this happen before? Any recommendations on fixing it?

Yesterday I went to the RV for a tool and decided to do the monthly of cycle the generator. Here's what I did:

- Turned on the main house power switch
- Turned on the factory-installed inverter by remote because it tells me how many volts the batteries are reading. It said 12.8v. I turned off the inverter.
- Primed the generator by the factory-installed remote switch. It primed, the switch turned red like it's supposed to, so I pushed start.

I heard a thunk...I think it was the generator turning over once, and then nothing. Here are the symptoms:

- No power in the house OR the motor. The only connection between the two should be the auxiliary start switch that lets me start the motor with the house batteries if the motor battery dies, and that wasn't pushed. Even the electric door locks don't work.
- Generator won't prime or turn over even when I use the switch ON the generator instead of the remote.
- RV motor won't turn over. I tried it normally and using the auxiliary start switch, and nothing.
- I checked the inverter one more time and it won't turn on.

I've only made two changes to the electrical system so far.
- New batteries. They use the same battery-to-RV connections as the factory.
- Ran an inverter off the batteries to its own outlet inside the RV. It isn't connected to any of the RV's circuits.

Some of you may remember my previous threads where I bought a whole-house inverter, but real life got in the way and I haven't installed it yet so no changes have been made to the factory electrical system except the new batteries.

To do for today:
- Check the fuse box. (Wasn't convenient yesterday.)
- Check each battery with the voltmeter to see if there's a problem with a single battery.
- Check for critter chewing underneath. We have possums around here, and mice outside, etc.

Any ideas?

[Just_Jeff]

Turns out the problem isn't entirely fixed...I was only halfway to a solution yesterday.

If I try to start the generator, the power shuts off in the house just like it used to. The indicator light on the main power switch acts just like it used to...if I try to turn off the power, the light glows dimly.

But if I crank the engine, the main power switch operates normally. Once I turn on the main power switch again (i.e., off and back on after cranking the engine), I can now use the 12v system and start the generator.

Also, when the engine is not cranked and I try to start the generator, I can hear the clunk as the house power goes dead. It's probably the latching relay or a sticking solenoid, from what y'all have said. But at least it's usable for the time being...I just crank the engine and start over.

Regardless, I drop it off tomorrow for a warranty appointment for several other issues. 😞 I'll add this to the list and let them take care of it.

Thanks again to everyone for the suggestions...this helpfulness is what makes this place feel more like a community.

[Just_Jeff]

I only turned on the inverter to see what voltage the house batteries were pushing b/c it has a rudimentary battery monitor on it. I mentioned it here to show that power was working before I tried to start the generator.

I think you're both right about the wiring, though...I need to figure out what powers what. I'm pretty sure the chassis battery doesn't get charged with the converter, and having the auxiliary switch powered by the chassis battery would explain why it didn't work this time. Shoddy workmanship, if that's the case...and completely defeats the purpose of the switch in the first place.

Anyway, family stuff today but now I know what I need to check on next week.

[MNtundraRet]

The one problem you have left is that your MH may not be set up to charge the chassis-battery when plugged in for converter/charger to charge the house-batteries. My Fleetwood Jamboree does but not true for all manufacturers.

That could explain the dead chassis-battery. Also; the inverter you have installed is used only for converting 12v dc off your house-batteries to 120v AC for television, or dedicated 120v ac outlets. It has nothing to do with your problem except if the dummies connected it to your chassis-battery.

The inverter should be left off unless powered to run an AC outlet. They can use upwards of an amp per hour, depending on size, if they are powered (not including additional for electronics plugged in.

[MrWizard]

RV's can be wired either way
many have the genset wired to chassis battery

it takes less power to start the genny than the drive engine

the problem with the 'emg jump start'
is many mfg wire the switch to the chassis side
a totally dead chassis battery will not power the relay

the switch is on the dash, and the mfg takes the easy way out
but IMO the emg jump should be wired to the house batteries to power the relay providing the jump

i have had almost dead chassis and very low house batteris
but was able to emg jump start the genset to power the converter to boost the batteries so i could then jump start the drive engine

[Just_Jeff]

I'm still unsure exactly what powers what, and why it affected both systems. I know the chassis battery powers the steps, though.

Have some experimenting to do.

[j-d]

Glad it's running.
But your summary confuses me. Genny should start from one batt/bank or the other.
suggest you find out what powers what. At least disconnect chassis bat and see what still works. Chassis bath usually powers what you'd expect plus perhaps the steps. Then house batt/bank powers house and genny. And again, perhaps steps.

[Just_Jeff]

Ok - it's all fixed now. When I reconnected the house batteries, everything worked like it never happened. I assume this means the generator starts off the chassis battery, and that the generator popped a relay or something when it turned over but didn't start. The relay was somehow reset when I disconnected/reconnected the house batteries, and when the chassis battery was charged.

Confusing how a dead chassis battery can have that effect across systems, but it's a good learning point for the future. Interesting how the auxiliary start switch was in place specifically to start the motor off the house batteries when the chassis battery is dead, but it didn't work this time.

Thanks to everyone for the suggestions!

[Just_Jeff]

First thing I did was test the chassis battery. It was dead. Topped it off and charging it now. So, there may be two unrelated problems...or the problems may be related.

I *think* the only connections between the chassis and house batteries are the alternator-to-battery connection to charge the house batteries while I'm driving, and the auxiliary start switch...so that shouldn't affect the rest of the house power. All three house batteries are pushing 12.8v.

It's possible the generator uses the chassis battery to start, though...which would explain the generator part, but I don't see how that could explain the rest.

MrWizard - the inverter is under the bed, next to the fusebox. I don't recall seeing any inline fuses but I'll trace the path and see if I can find any. Going back out to check all the fuses in the box in a second.

Thanks everyone for the help so far!

[MrWizard]

Maybe I missed it but the one thing I didn't see mentioned was a fuse
There should be a fuse between the inverter and batteries
A catastrophic fuse would be located close to the batteries
And more likely to be inline with the inverter or genset than the latching relay which disconnects the house 12v
And could possibly be inline with everything

[j-d]

This one at Makarios looks a little different.

Maybe it connects differently, maybe those extra wires turn that indicator light on.

[j-d]

Another troubleshooting/repair tip:

Check the GROUND side as carefully as you check the HOT side of any wiring!

This is the Link I Found it on. There more be more advantageous sources. I like MakariosRV, also don't rule out eBay and Amazon. I just grabbed this one because I've been able to post their pix before. Some sites don't work as well for me.

[Just_Jeff]

j-d - that's the switch I'm talking about. I'll see if I can find the Latching Relay.

[j-d]

In your first post, you

"- Turned on the main house power switch"

And in your most recent post,

"main power switch has a light when it's powered on"

Which Switch is this? I'm taking it that the one you mention (close to the door step well in our Jayco) is the Battery Disconnect, that you shut off when not using the coach so the parasitic stuff like LPG Detector don't run the battery down. Is that correct?

If so, sounds to me like the Latching Relay near your House Batteries has failed. Guy that looks like this?



Disconnect your house batteries again, check the connections at that relay, and try again. If you can do this safely, without grounding to metal surrounding the relay, you could use a jumper cable to connect the two large terminals of the relay. That would bypass it and you could see what works then.

I forget the details, but if I recall correctly, there are two versions of those relays. Different in how they are energized to Latch and Un-Latch.

Be sure you understand "Latching" It means the Relay is powered intermittently and stays in whichever position it flipped to. Then no power is required to keep it there, only to flip it again. Think of a ballpoint pen. Click to Extend and it stays, Click to Retract and it stays. It may LOOK like a "starter solenoid" but it isn't since those don't latch. They're like a ballpoint you have to hold down to keep the point out.

[Just_Jeff]

MNTundra - thanks for all the info. There was nothing wrong with the old battery; I just upgraded from the cheap OEM house battery to three 230AH SLA batteries.

Your diagnosis sounds plausible from what I know now. If the solenoid is stuck, how can I get it unstuck? Can I just jump start the chassis battery and then retry the generator?

One other detail I forgot to mention. My main power switch has a light when it's powered on. Now the house won't power on, but when I flip the switch, it pauses a second or so and then the light slowly starts to turn on. A little dimmer than normal, and it doesn't turn off when I press it again. I disconnected the batteries when I saw that.