Sunday, May 28, 2023


Why doesn’t RV’s slide out work when plugged into house power?

Dear Dave,
I’ve had the RV plugged in during the winter on house power, starting it about once a week. All of a sudden the RV’s slide out and rollout canopy stopped working. I have not checked the fuses, but it keeps blowing the house power, also. Do you have any insight, please?—Richard, 2021 27-foot Thor Freedom Elite

Dear Richard,
The Thor Freedom Elite is a Class C motorhome on a Ford Cutaway Chassis and has two separate power supplies for the house systems. When you are plugged into a shoreline source such as the campground pedestal or by use of a generator, 120-volt power is supplied to the distribution center. This has a main circuit breaker and individual ones for the 120-volt appliances and outlets such as the roof air conditioner, refrigerator on 120-volt mode, and outlets for microwave and other appliances.

You also have a 12-volt system that has either one or two 12-volt deep cycle batteries that are typically housed either in an outside compartment behind the passenger side door or under the entrance steps. The deep cycle house batteries power items like interior lights, roof vents, water pump, and also provide power for most LP appliances. The distribution center has automotive-style fuses that protect each of these circuits.

Typically the slide room mechanism is powered by the house batteries, so if it is not working, it should not affect the 120-volt system and should not trip the house circuit breaker. However, I’ve learned to never say never when it comes to RVs and how manufacturers build them! So, I believe there are two separate issues that seem to be one.

Troubleshooting slide room not working

First, let’s look at the slide room not working. With the mechanism being powered by the house battery or batteries, we start looking there. Since you are plugged in, 120-volt power is going to the distribution center. One of the components is a converter which provides 12-volt power to the batteries, which in turn provides 12-volt power to the slide room mechanism. As you suggested, check the fuse in the distribution center to make sure it is not blown. With the unit plugged in, your converter will be providing at least a 13.2-volt charge to the batteries. I would suggest using a multimeter to verify there is power at the battery/batteries.

From photos and videos I find online, it looks like the driver side full slide has an in-wall mechanism, as there are rails at the top and bottom of the slide room itself. This could be a Schwintek or the Lippert newer version. However, they both have motors in the walls and a controller in an underneath compartment. If the room is not working, the controller should have an error code which will help identify the issue. Visit and you can identify what mechanism your unit has and follow the troubleshooting.

What could be tripping the house breaker?

Now let’s look at what is tripping the house breaker. Since you stated the unit is plugged into “house” power, I assume you are plugged into an outlet in the garage. That is typically a 20-amp circuit that has other outlets “ganged” to that circuit. It might have something else drawing power such as a refrigerator, freezer, or air compressor. It is always best to have a dedicated circuit for your RV. I recommend a 30-amp circuit to make sure it does not get overloaded.

The next step is to identify what is drawing power from that circuit. Even if nothing is turned on such as the refrigerator, the converter will provide a constant 13.2 volts when plugged into shoreline power. Depending on the size of converter and the battery bank, this could be anywhere from 6 amps up to 12 amps? One way to verify most of the components are shut off is to physically shut off the circuit breaker for everything except the main and the converter and see if you still have the issue.

One possibility to check for

You did not state specifically when the circuit breaker was tripping. However, if it happens at the same time you try the switch, the only thing that could be happening is the motor tries to move the slide, which puts a draw on the house batteries. If the batteries are sulfated they would take what we call a “deep dive” in voltage and the converter would sense a charge is needed and kick into 13.6 volts, which might be too much for your circuit. If you have a multi-stage charger such as an inverter/charger, it would kick into a bulk charge to break up the sulfation at anywhere from 14-16 volts.

Unplug the unit, use a multi-meter to check the battery condition, then plug the unit in leaving the multi-meter on and see what voltage it registers. That will tell you what type of converter you have. Next, leave the multi-meter on the battery and the unit plugged in, then hit the switch and see what the voltage reads at the battery.

Check the amp draw at the outlet

Another step would be to find out what amp draw you are getting at the outlet. If you have a surge protector like the Southwire Surge Guard, plug it in and you will see the voltage as well as the amp draw. Then you can hit the switch and see what is happening.

If you don’t have one of these, go to a home improvement store and get an inexpensive Kill A Watt™ meter that will give you the same readings. Or find one on Amazon here.

If you are under the amp rating of your circuit breaker, then you have something else in the garage or on the circuit that is making it trip. Or it could be a weak circuit breaker. I had an issue in our garage that had a GFCI breaker on the actual circuit breaker that was too sensitive for me to plug in just about anything that had a little spike at start up. I had to have an electrician install a heavy duty breaker in its place.

 You might also enjoy this from Dave 

What are the types of RV house batteries and what do the acronyms stand for?

Dear Dave,
Readers appreciate very much your RV tech wisdom. Could you provide an article on the various battery types available for RVs, those useful for solar power when off-grid and what all the acronyms mean? Thanks. —Colin, 2020 Jayco 26.7

Read Dave’s answer.

Dave Solberg is a leading expert in the RV industry and the author of the “RV Handbook.”

Read more from Dave here


We have a popular forum for Ask Dave. Please be as brief as possible. Attach a photo or two if it might help Dave with his response. Click to visit Dave’s forum. Or send your inquiries to him using the form below.

Click or drag a file to this area to upload.


Dave Solberg
Dave Solberg
Dave Solberg is a leading expert in the RV industry and author of the “RV Handbook” as well as the Managing Editor of the RV Repair Club. He has been in the RV Industry since 1983 and conducts over 15 seminars at RV shows throughout the country.


4.8 5 votes
Article Rating
Subscribe to comments
Notify of

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Inline Feedbacks
View all comments

Sign up for the

RVtravel Newsletter

Sign up and receive 3 FREE RV Checklists: Set-Up, Take-Down and Packing List.