12V Power Problems

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grubbie

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Joined
Sep 27, 2021
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9
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FDL, WI
I have a 2013 Jayco Greyhawk, and my 12v power cuts out then comes back on. It comes and goes every few minutes, seemly at random. This happens when the RV is parked and when the engine is running. I took the battery to AutoZone and had it tested, and it tested out fine. If anything the guy from AutoZone said it was over charging.

I checked the fused box, all looked good in there. The connections to the battery looked good, and it is a new battery.

I recently upgraded from a pop up camper, so that is the extent of my trouble shooting skills.

Does anyone have any thoughts on where to go from here?

Thank you
 

grubbie

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Sep 27, 2021
Posts
9
Location
FDL, WI
Does the engine stop running too? Please describe in detail what does happen.
The engine stays running. All of the lights turn off, the screen for the radio/cameras turns off, and the fridge stops running. It is like I disconnected the battery for a moment and then it comes back on. I have checked the battery gauge in the RV and even when the engine is running and it'll be any where from 1/4 to 3/4 charged despite not using very much power.
 

Henry J Fate

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Jun 14, 2018
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1,593
You may have a auto reset breaker in your 12 volt supply line that is tripping and then resetting due to a problem or possibly a bad breaker. You could also have a bad connection somewhere.

It is difficult to pinpoint a problem such as this without contact with the RV but most certainly you need to trace this problem and solve it.
 

NY_Dutch

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Where our wheels take us!
When parked for awhile, try connecting a jumper cable from the house batteries ground post to a known good frame ground point. If the intermittent problem stops, start checking ground points for a loose or corroded connection. Or start chasing the grounds anyway since they're a relatively common failure point.
 

Bobtop46

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Bronson FL
I second NY Dutch it is an intermittent ground or loose connection somewhere. One other possibility is a 12v cutout (storage or salesman) switch at the door has a bad connection.
 

Great Horned Owl

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I second NY Dutch it is an intermittent ground or loose connection somewhere. One other possibility is a 12v cutout (storage or salesman) switch at the door has a bad connection.
The salesman switch doesn't disconnect the battery directly. It operates through a relay or solenoid, that might be intermittent, or have bad connections.

Joel
 

Kirk

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If you have a battery isolator switch, I would suspect that first. An easy way to be sure is to move both cables to the same post of the isolator so that it does nothing. If the problem is gone, you know, if not put it back. The problem has to be between the battery and the 12V distribution panel. Since it happens with the engine running it also means that the problem is between the fuse panel and wherever the 12V from the engine connects. that varies from one RV to another since it is put in by the coach builder. There is a solenoid that ties the two systems together when the engine is running and if you trace the cable from that solenoid to the point where it connects, the problem must be between that point and the distribution panel. Some RVs will charge the battery with the battery isolator open while others will not. You need to know where yours connects. If your 12V distribution panel has a master fuse or circuit breaker that will turn off all power, that could be the cause.
 

Gary RV_Wizard

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At our Silver Springs FL home
I lean toward the auto-reset circuit breaker as the immediate cause, but it would depend on whether the power restores itself immediately or after some delay. And if it is a breaker, then the question becomes why is it tripping like that? A faulty breaker is well down the list as the reason.
 

Henry J Fate

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Hire an electrician. We can't trace intermittent electrical problems long distance.
An electrician would not be a practical hire to solve this problem. A good understanding of RV design and builds is required.

An RV tech with good build knowledge would be a good choice.
 

John From Detroit

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Apr 12, 2005
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25,274
Location
Davison Michigan
Not a DC issue but an AC issue. When my Motor home was new sometimes the Front Air Conditioner worked, sometimes the rear sometimes both or neither Ok, so I decided "Good chance it is electrical" and since that's my "Juristiction" (Well Certified ELECTRONICS technician) I started at the power distribution panel... .... One screw took over 3 full turns to tighten(A few others needed tightening as well) .. after that everything worked fine.
Also the radio would cut out. Oh it showed it was workign but no sound.. Well I have a relay box that switches the speakers between the HOME theater and the Dash Radio.. One of the multi pin connectors .. when I pressed on it I heard the SNAP SNAP of the Molex latches latching..... Yup. that was it.

Many connectors, some screws. Some push in's and they dont' always push in all the way or tighten.

100,000 dollars and screws lose.... Yup... )(@#%*)@#([email protected])#($*)[email protected]~!
 

Kirk

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And if it is a breaker, then the question becomes why is it tripping like that?
In that same line of thought, can you think of anything that happens just before or just as 12V power is lost? Consider even the most simple things as if you can come up with anything common to the times you lose 12V that would be a major hint to help in figuring out what is causing it.
 

grubbie

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Sep 27, 2021
Posts
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Location
FDL, WI
Wow, Thank you for all the help. I will take a look this weekend, at this point I think I will start at the top of the list and work my way down.

I'll keep y'all in the loop.
 

grubbie

Member
Joined
Sep 27, 2021
Posts
9
Location
FDL, WI
Hello,

I I think I found the problem. This guy was located in the battery compartment, and that resistor was rubbing against a bolt. As I was trouble shooting I couldn't find anything else that looked amiss. So hopefully this solves it. Fingers crossed.


image1.jpegimage0.jpeg
 

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