Start at the Source

🔌 RV Outlets Dead and A/C Not Working? The Power Pedestal Was the Problem
RV Type: 2018 Heartland Bighorn Fifth Wheel
Service Date: June 2, 2025
Issue: Air conditioner not working, multiple dead outlets, and an E7 error on the Dometic thermostat

🔍 The Problem
A customer contacted me with several simultaneous electrical issues on their 2018 Heartland Bighorn:

• One A/C unit wouldn’t turn on

• Interior outlets weren’t working

• The Norcold refrigerator was showing a low or no power message

• The Dometic thermostat displayed an E7 error code

By the time I arrived, power had failed completely at several points in the RV, and the fridge had shut down entirely.

🧰 Diagnosis
My first instinct was that the house batteries were draining, likely due to the converter not charging properly. I started searching for the converter to test its DC output—but quickly realized it was deeply buried in a compartment and tough to reach.

So I stepped back and went to check the basics first.

The customer casually mentioned that a neighbor had recently been spraying water near the campground power pedestal. That detail raised a red flag.

At the pedestal, I tested for incoming shore power. Sure enough, one leg of the 50-amp service was dead—explaining the partial power loss throughout the coach, the E7 error (which points to communication or power issues), and the slow battery drain.

✅ The Fix
Fortunately, the customer had a 30-amp to 50-amp dogbone adapter on hand. I plugged the RV into the 30-amp outlet to bring at least one leg of power back online.

This temporary fix allowed the converter to come back up, which in turn began charging the drained house batteries and restored function to some key systems.

⚠️ Important Note: The 30-amp breaker at the pedestal was also weak and tripping easily—even with a single A/C unit running. I notified the campground and requested they replace the breaker along with repairing the faulty 50-amp socket.

🧠 What Caused It
This wasn’t a converter or RV system failure—it was a classic case of incomplete shore power due to a campground pedestal issue. When one hot leg drops out on a 50-amp service, you may see:

• Half of your outlets go dead

• Appliances like fridges or A/Cs shut down

• Thermostats and control boards show error codes

• Batteries begin to drain due to lack of converter input

💡 Takeaway
When dealing with multiple odd power issues in your RV, don’t overlook the pedestal. A bad socket or missing leg of power can mimic all kinds of electrical system failures inside the coach.

And always carry a dogbone adapter—sometimes it’s the quickest way to restore partial function until full repairs can be made.

🔧 Experiencing strange power issues in your RV?
I’m a certified mobile RV technician serving the Mississippi Gulf Coast. Whether it’s a dead air conditioner, an overloaded breaker, or a faulty campground hookup, I’ll help you get powered up and back to enjoying your RV.
Contact me today for reliable mobile RV service.