I have an new electric issue that I need to troubleshoot tomorrow and am looking for advice.On DC (2 x 6V) lights are good, power shows full (also metered at batteries 13ish). When the water pump kicks on it dramatically slows down, the lights dim, then it’s like the power is cut as the propane detector beeps (the low power beep) then everything clicks off. Then everything comes right back on and lights are bright as can be. Checked the voltage at the batteries while this happens and it shows a slight drop. On shore power no problems at all. I didn’t have a lot of time to dig into it so far, but assume it has to be either something in the converter, or batteries.Thoughts?

I think you probably have a poor connection somewhere between the battery and the DC distribution panel, quite possibly at the main self-resetting circuit breaker for the battery (or possibly inside that circuit breaker). A poor connection there would not only cause a voltage drop, but would also make the circuit breaker warm up a good bit and so trip at well below its rated current. That said, there may be a poor connection in many places, and it could be on either the positive or the ground side. Go through and check that all the joints are clean and tight, and the wires have not corroded away (particularly those attaching to the battery).

D MAX wrote:On DC (2 x 6V) lights are good, power shows full (also metered at batteries 13ish). When the water pump kicks on it dramatically slows down,....Checked the voltage at the batteries while this happens and it shows a slight drop. On shore power no problems at all.I need clarification on this. "On DC". Does that mean on batteries alone without the converter running? 13ish is not the resting voltage of any battery, so it sounds as if the converter is on, but then later you say.."On shore power..." (which runs the converter).thanks

DrewE wrote:I think you probably have a poor connection somewhere between the battery and the DC distribution panel, quite possibly at the main self-resetting circuit breaker for the battery (or possibly inside that circuit breaker). A poor connection there would not only cause a voltage drop, but would also make the circuit breaker warm up a good bit and so trip at well below its rated current. That said, there may be a poor connection in many places, and it could be on either the positive or the ground side. Go through and check that all the joints are clean and tight, and the wires have not corroded away (particularly those attaching to the battery).Thank you, that makes sense. The battery terminals are clean and tight, so I’ll work my way back to the converter.

2oldman wrote:D MAX wrote:On DC (2 x 6V) lights are good, power shows full (also metered at batteries 13ish). When the water pump kicks on it dramatically slows down,....Checked the voltage at the batteries while this happens and it shows a slight drop. On shore power no problems at all.I need clarification on this. "On DC". Does that mean on batteries alone without the converter running? 13ish is not the resting voltage of any battery, so it sounds as if the converter is on, but then later you say.."On shore power..." (which runs the converter).thanksYa sorry that may have been confusing. On DC was just running off of the batteries. I metered them after all this started, and had been running lights, fans and the pump several times to troubleshoot. I can’t recall if it was 13.2 or 13.4. Should also note I have a solar panel.When on shore power there are no issues.

Find the exact spot where the converter enters the power to the fuse panel.At that exact spot, start testing backward to the batteries. I've got an ESPN feeling you are dealing with a flaky negative junction. My crystal ball is 74 years old so don't throw tomatoes if it turns out to be on the positive cables.

Power cuts out when pump runs (on DC) | Good Sam Community

enblethen
Nomad
Jul 28, 2020
If you have an old bicycle inner tube, a short piece slid over wires and then back over circuit breaker will protect it.
D_MAX
Explorer
Jul 28, 2020
enblethen wrote:
Is there room to put it inside battery box?
Coat terminals with electrical grease

That's a good idea. I'll have to do some rewiring as the existing cable wouldn't reach but it would be worth it.
enblethen
Nomad
Jul 28, 2020
Is there room to put it inside battery box?
Coat terminals with electrical grease
D_MAX
Explorer
Jul 28, 2020
Ya I'm going to replace the breaker as they're cheap.

The previous one only had shrink wrap on the posts but the nuts and connectors were exposed (mine was mounted on the tongue under the battery box, full bathtub in effect). I'll try and rig up something to protect the new one better.
Bobbo
Explorer II
Jul 28, 2020
enblethen wrote:
I would replace it with a new auto-resetting circuit breaker. Make sure it is protected from water including road spray.

I second the suggestion to put another self-resetting circuit breaker in.
Lynnmor
Explorer
Jul 27, 2020
enblethen wrote:
I would replace it with a new auto-resetting circuit breaker. Make sure it is protected from water including road spray.

Many of the breakers used are shaped like a bathtub and are mounted with the tub upright so it collects water. I mount with the tub upside down.

example
enblethen
Nomad
Jul 27, 2020
I would replace it with a new auto-resetting circuit breaker. Make sure it is protected from water including road spray.
D_MAX
Explorer
Jul 27, 2020
Update and problem solved:

I couldn't replicate the problem until recently. Previous to that I had verified all connections were clean and good. But on our last trip out it finally happened again. Starting at the batteries and working back I didn't have to go far (Thank you DrewE). It was the self resetting circuit breaker. With lights on and pump running the voltage going into the breaker was normal, but the output side would drop significantly and bingo everything blacked out.

The difference now was the power was out longer whereas previously it rebounded instantly. With every repeated failure the power seemingly stayed out longer. So while the breaker was already failing, it's definitely on it's last legs now. I don't totally understand why the problem couldn't be replicated until now as I thought once mechanical breakers start to go they are basically toast.

I had a spare 30A in-line fuse that I put in place and life is good. I haven't decided if I'll replace the breaker, put a manual resetting one in, or just leave the fuse.

Thank you to everyone for your help and advice!
D_MAX
Explorer
Jun 23, 2020
Gjac wrote:
Another thing to check is the set screws that hold your 12v wires in place on either side of the 12 v fuses a loose screw could cause an intermittent problem.

Thank you, I’ll definitely check them.

Because this is intermittent and currently not a problem, it’s going to be more frustrating as I may not be able to actually ID the fix unless it’s super obvious. My weekend ahead will be the joy of going over all connections and insuring I have good grounds.
Gjac
Explorer III
Jun 22, 2020
Another thing to check is the set screws that hold your 12v wires in place on either side of the 12 v fuses a loose screw could cause an intermittent problem.

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Power cuts out when pump runs (on DC)

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