A battery disconnect switch is an important part of any travel trailer. It helps to protect the battery from draining and can save you a lot of trouble in the long run. But sometimes, there can be an issue, and you may need to do some troubleshooting. Common problems are:
- Dead RV Battery
- No Power to RV
If you are experiencing any RV battery disconnect issues, this post will help you uncover common problems and solutions.
Table of Contents
- What is a Battery Disconnect Switch
- Problem with RV Battery Disconnect Switch
- Final Thought
What is a Battery Disconnect Switch
Essentially, an RV battery disconnect switch breaks the electrical connection between your RV battery and other electrical systems in your trailer when you’re not using them. This prevents your battery from powering unnecessary components such as lights or smoke detectors while parked and keeps it at its full charge so that when you are ready to hit the road, you don’t have to worry about running out of power.
Even when connected to shore power, the battery disconnect should still work correctly and disconnect power to your house battery.
Your RV electrical system provides 12 volt power using both the positive and negative terminals from your trailer battery. Regardless if you have an AGM battery, lithium battery, lead acid battery, or deep cycle battery, the electrical power is disconnected the same way.
And with a battery disconnect, it only needs to disconnect one battery cable (usually the positive cable) to cut the electrical power to your travel trailer.
Problem with RV Battery Disconnect Switch
There can be a few problems you are experiencing with your disconnect switch. Each specific situation may have a different solution. Let’s review common issues and solutions with the switch.
Dead RV Battery
If your issue is that you have a dead battery while the disconnect switch is off, you will have a couple of things to check. The main suspect is that the battery disconnect is not cutting off the power from the battery to your RV. And the draw of power in things like your smoke detector and the clock will continue to drain your battery until you have a dead battery.
First, check to see if your switch is fully turning to the off position. Since the disconnect switch is a round knob, it may appear fully rotated and disconnected. Turn the switch back on, then off as entirely as possible. See if that resolves your issue.
If the battery switch is fully rotated and you still have an issue with a dead battery, likely the problem is a bad switch. That is because it still allows current even though it is set to disconnect the power.
One way to check for sure is to get a multimeter. Go to the disconnect copper posts (where the battery cables are) and see if you are getting continuity between the posts. If you are getting continuity in the off position, power is still going through your cables, and the disconnect switch is faulty.
You’ll need a multimeter and two probes to check for electrical continuity. Connect one probe to each end of the wire and use the meter to measure the resistance between them. If the resistance reading is close to zero, you know your wires have good electrical continuity. It’s also important to ensure that no other wires are connected for accurate readings.
This is the opposite problem of the dead battery above. And that is no power to your trailer even though the disconnect switch is on. If you are experiencing this issue, try these steps.
First, try the turn-on and then-off trick you read above. This could still be a similar issue in that the disconnect is not fully engaged in the proper position.
If you are still not getting power, it could be a connection issue with the battery cable, the battery terminal, or the battery itself. Let’s start first with the battery. Check the battery terminal to make sure that the posts are clean and that there is an excellent connection to the battery cable.
Next, check the battery cable for the battery to the RV disconnect switch (again, this is usually the positive cable). This cable could have damage or corrosion. Check to see if you have any rodent damage or any breaks in the cable sheathing that would cause an issue.
Finally, check the connections at the battery disconnect switch. Like the battery terminals, the connections should be secure and clean with good metal-to-metal contact. If you have good and clean connections on all these parts, the electrical system should provide the 12 volt power needed.
If you have passed all the steps above, this could be a faulty RV battery disconnect switch. Let’s grab the multimeter again. In this case, you want continuity between the disconnect posts in the on position. Remember, the main function of the disconnect is to disrupt the power flow between the battery cable. And if you are not getting continuity while the switch is on, it is not working correctly and is faulty.
Different issues can cause RV Battery Disconnect Switch Problems. A dead battery, even though the disconnect switch is in the off position, indicates that the switch is either not fully rotated or faulty. At the same time, no power at all to your travel trailer in the on position is a sign of a bad connection anywhere from the battery terminal to the disconnect switch itself.
Tony is an avid camper and RV traveler. He fell in love with camping on his first RV trip with his wife over 25 years ago. Tony loves sharing lessons learned and tips about RV maintenance and safe traveling.