Help please with 12volt

[vfauto]

We are away from any kind of authorized repair facility and we are having a problem with the 12 V system. It intermittently shuts down, if I am watching the voltage you can tell when it's going to do it, it starts dropping from 12.9 down to 10-ish and then the whole 12 V system shuts down,30 to 60 seconds later everything comes back on. The shore power seems fine I don't have any error codes on my progressive surge protector. I called Newmar customer service and they want me to bring it to a authorized repair facility. They will not walk me through any kind of testing because it's under warranty. I am 100% capable of diagnosing this problem if I have information from Newmar. I am a automotive master technician along with a license electrician.

[Smosher]

You might try completely unhooking the batteries I know in the past that it has on some coaches this resets the computer. Sounds like a ground or inverter, you might check the reset buttons on the inverter. You could start by just turning off the house batteries at the switch. Sounds like the inverter went bad.
Steve

[vfauto]

Why are you leaning towards the inverter? If I watch the voltage on the monitoring system it drops from full voltage to 10 and then everything goes off for 30 to 60 seconds.

[J Birder]

It sounds very much like a loose connection. Does this happen when you are on shore or generator power, when you are running on batteries?

Joel

[GaryKD]

Hi vfauto,
Because the coach is new, consider there is a weak component in the 12 VDC supply circuit. Loosing all voltage would mean the weak component is in the part of the circuit from the coach batteries to the EMS. This could be a resettable fuse inline from the batteries. It could also be a problem in the EMS itself.

One question, do you actually lose 12 VDC throughout the coach? I referring to the items powered directly from the coach batteries. Lights would be the easiest to determine if all power is actually being lost. The reason for asking is to determine if the measuring device reporting a loss of power but the lights remain on. Trying to determine the measurement from reality.

[vfauto]

Yes we lose all 12 V power just like shutting the disconnect switch off lights and everything go out

Originally Posted by GaryKD

Hi vfauto,
Because the coach is new, consider there is a weak component in the 12 VDC supply circuit. Loosing all voltage would mean the weak component is in the part of the circuit from the coach batteries to the EMS. This could be a resettable fuse inline from the batteries. It could also be a problem in the EMS itself.

One question, do you actually lose 12 VDC throughout the coach? I referring to the items powered directly from the coach batteries. Lights would be the easiest to determine if all power is actually being lost. The reason for asking is to determine if the measuring device reporting a loss of power but the lights remain on. Trying to determine the measurement from reality.

[vfauto]

What does EMS stand for, electrical management system?

[GaryKD]

Hi,
EMS = Energy Management System. Sorry for the delay, I'm thinking about this.

[GaryKD]

Have you added anything in the garage with regard to 12 VDC electrical.

[Skip426]

If your system goes from 12.9 volts to 10 volts while you are watching a gauge,( if I'm reading your post correctly) you could have a bad battery.

12.9 volts would indicate a battery bank at full charge, if your converter/charger is shutting off and resetting could be it is overheating trying to charge a bad battery, and a rapid voltage drop when the charger kicks out would indicate that the 12.9v is just a surface charge.
JMHO: first thing to do would be remove the batteries for a load test.

[Rotten-Red]

Originally Posted by vfauto

We are away from any kind of authorized repair facility and we are having a problem with the 12 V system. It intermittently shuts down, if I am watching the voltage you can tell when it's going to do it, it starts dropping from 12.9 down to 10-ish and then the whole 12 V system shuts down,30 to 60 seconds later everything comes back on. The shore power seems fine I don't have any error codes on my progressive surge protector. I called Newmar customer service and they want me to bring it to a authorized repair facility. They will not walk me through any kind of testing because it's under warranty. I am 100% capable of diagnosing this problem if I have information from Newmar. I am a automotive master technician along with a license electrician.

How fast does it drop from 12.9 down to 10-ish? When it resets after 30 to 60 seconds does it immediately return to 12.9 and again drop to 10-ish. Sounds like a short causing the voltage drop, which is tripping an auto/reset circuit breaker.

[vfauto]

No.added nothing in the garage

[vfauto]

That was my first thought (battery ) I am at a competition for my daughter I won't be able to check it till later

Originally Posted by Skip426

If your system goes from 12.9 volts to 10 volts while you are watching a gauge,( if I'm reading your post correctly) you could have a bad battery.

12.9 volts would indicate a battery bank at full charge, if your converter/charger is shutting off and resetting could be it is overheating trying to charge a bad battery, and a rapid voltage drop when the charger kicks out would indicate that the 12.9v is just a surface charge.
JMHO: first thing to do would be remove the batteries for a load test.

[vfauto]

When it does it it drops from 12.9 to 10 in less than a minute

Originally Posted by Rotten-Red

How fast does it drop from 12.9 down to 10-ish? When it resets after 30 to 60 seconds does it immediately return to 12.9 and again drop to 10-ish. Sounds like a short causing the voltage drop, which is tripping an auto/reset circuit breaker.