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RussM311 · 06-13-2025, 09:28 PM

Both A/C units were working fine.... I saw there was a storm coming and switched off shore power at the pole.... leaving the power cable plugged in with the surge protector in place. Came back to the rv this morning and neither of the units will work... getting different fault codes E1, E7.... and the units try to come on after the thermostat is turned off. Lots of flickering on the thermostat.... Disconnected from shore power and tried it on generator power... same result.

Replaced the thermostat with a new one and still the same...

Anyone have an idea???

Thank you and have safe travels.
Rusty

BLUEMETEOR · 06-13-2025, 09:36 PM

I googled "newmar 3953, a/c faults E1 and E7" and there were lots of hits, even some for your exact year.

rarebear.nm · 06-13-2025, 10:15 PM

What brand is the surge protector? What do those error codes translate into, E1 & E7 does not mean much alone. That will probably give you a good clue.

Is the surge protector before or after the transfer switch? If after it sounds like it did it's job and died to save the rig.

If really concerned about a storm unplug the cable from the coach. I've seen weird stuff happen on ground wires. Turning off the breaker does not disconnect the ground lead.

Since both ACs are down the problem is most likely something common to both units. There's not much in that category.

twinboat · 06-14-2025, 05:11 AM

Surge protectors don't protect against lightning. if your switching off shore power, you should also be unplugging the cord. The neutral and ground are still connected with just the breaker off, and lightning that traveled thru miles of air can jump across the 1/8 gap inside the breaker.

Any other electronics effected, like the microwave ?

doc · 06-14-2025, 05:21 AM

Sounds suspicious that both units stop at the same time. If your surge protector is a plug in type, then I might try taking it out of the line and see if that allows the units to start.
My coach has a surge protector the previous owner installed in the line. I had a problem similar to yours and was pulling my last few hairs out until I saw the red light on it shining. I ended up replacing the in-line SP and all went back to normal.
I am betting your situation/solution will be just as easy to solve

OMMM4747 · 06-14-2025, 05:38 AM

Recommend manually tripping and resetting the breakers. Any other electronics affected? TVs, fridge, etc.? Maybe a bad pedestal?

Twinboat is correct in that surge protectors will not safeguard against lightning strikes, which can strike miles away and travel through the lines. Always disconnect from the pedestal.

Good luck

YC1 · 06-14-2025, 06:01 AM

Have you measured battery voltages?

The 12 volts is critical to run many AC units. Power off, inverter left on, dead batteries. Power back on, battery voltage may or may not come back up for whatever reason.

And even if the batteries did come back to full charge, the Brown Out could have confused the control boards.

See if there is a reset procedure for your units.