water pump makes LEDs flicker on 12V only

[aukman]

We have a 2015 ST29SS
All our lighting is LED.
When on 120V (either 15A or 30A) we have no issues whatsoever.
When on battery (12V) and running the water pump, all the cabin lights flicker. Individually switching off each light reduces the flicker in the ones remaining on, so it appears as a load issue perhaps.
We have 2 12V batteries wired in parallel. Battery terminal connections are clean and tight.

Has anyone else had this issue and had it resolved?Any suggestions as to where I should be looking to troubleshoot this?

Many thanks!

[Lloyd]

Did your rig come from the factory with LED lights?

It's possible that it could be a poor ground, but that seems pretty remote seeing as your rig is new.

[aukman]

Thanks Lloyd, I will take a look but yes, this is all factory installed. I'd rather troubleshoot and fix myself than take it to my dealer (haven't had great experiences with them in the past, sadly).

[Lloyd]

Just another thought.
While you are looking things over, maybe you should check the connections on the back of the breaker and fuse panel, also the converter. There has been posts where others have found some of those loose.
Just make sure you have all the power disconnected before starting.

I don't know how good the LEDs are that come with the new rigs. I haven't had any personal experience with them. Hopefully they are better then the lights they put in the awnings.

[r2millers]

So you know your converter is working properly so when plugged in to shore power, it's supplying enough amperage to operate the 12v water pump without issue.
However, without shore power, the battery 12v is supplying the source of power and that's not enough to keep it from flickering.
I agree with Lloyd that it sounds like a grounding issue off the battery or the connections before the pump if the batteries are in good shape. Expect to see 12.6-12.8 volts when testing them static.