RV’s, like any home or automobile require frequent repairs and maintenance. At Coach Specialists here in Dallas, we are in business to repair RV’s of all shapes, sizes, makes and models. When customers drop their Rv’s off at any of our Dallas and Fort Worth shop locations, we usually get a laundry list of repair items that need to be done. Even though we specialize in collision repairs, we work on all systems and can handle warranty repairs. As a result we are very knowledgeable in most rv repair needs. One issue that we run into frequently is electrical issues.
In an RV, most of the devices and accessories operate off of 12-volt DC power which is electricity supplied by the RV batteries. DC electricity flows in one direction, from negative to positive. 12-VDC electricity is stored in the RV batteries and supplies power for components, devices and appliances that operate off of 12-volts.
Any number of the devices in an RV run on 12-volt circuits including overhead lights, the water pump, vent fans, furnace fan, range hood fan, LP gas leak detectors, stereos, 12-volt TVs and even the refrigerator when it’s operating in the LP gas mode. When you go camping in an area without the luxury of RV hook ups, you rely on these 12-volt items to operate properly. So what do you do when one of these 12-volt appliances stops working?
With a little knowledge, anybody is capable of troubleshooting a 12-VDC problem, and in many cases repairing the problem without it ruining your camping trip. For starters you will need a couple of simple tools to assist you in troubleshooting your RV’s 12-volt electrical system.
1). An inexpensive 12-volt test light.
2). A multi-meter that can test for DC power.
Both of these are available at local auto parts stores. You should also keep some electrical tape, various size wire nuts, 12-volt light bulbs and 12-volt fuses on hand. Check the amperage of the fuses used in the power distribution box and keep an assortment. If you’re aware of any inline fuses used on any of the 12-volt devices keep these on hand too.
First step is isolating the issue
Try to pin point the last time the appliance actually worked. Did you leave the RV for a period of time with the Appliance on? Were you working on or around something else that could have affected the operation of the appliance? Try to think of all possible scenarios. Something might jar your memory resulting in a quick fix to the problem.
Next step- Verify battery condition
Determine and verify that the RV battery or batteries are charged enough to supply power to these 12-volt items. There are a couple of ways to perform a quick test on the coach batteries. You can use the monitor panel to check the condition of the coach batteries. To get an accurate reading make sure the RV is not plugged into electricity and turn on a couple of overhead lights to place a small load on the battery. Check the reading at the monitor panel.
Note: If you check the reading at the monitor panel when the RV is plugged in to electricity it will give you fully charged reading.
Grab your multi-meter
A more accurate method is to test the battery with a multi-meter. Set the meter to read 12-VDC and place the negative test probe on the negative battery terminal and the positive test probe on the positive battery terminal. A fully charged battery will read in the range of 12.6 to 12.7 volts. If it reads less than 12-volts it is below a 50% state of charge and will need to be charged.
Check the Battery disconnect switch
It is easy to overlook the battery disconnect switch even for more experienced RV users. If the battery is fully charged, the next step is to make sure that any battery disconnect switch for the coach battery is turned on. If the battery disconnect switch is on, verify that other 12-volt devices in the RV are operating properly.
If there is 12-volt power to the interior of the RV you need to check the fuse for the appliance in the power distribution center. Determine which fuse is for the Appliance circuit (fuses are normally labeled) and find a suitable ground for the 12-volt test light. Test both sides of the fuse for 12-volt power. If the test light only lights on one side of the fuse replace it with the proper size fuse and try the appliance again. If there was power at both sides of the fuse, check for 12-volts at the appliance switch, or outlet. If there is voltage, and the switch is operating properly check the appliance wiring for an inline fuse.
Find a good ground for the 12-volt test light and probe the wire on both sides of the fuse. If there is only power on one side of the fuse replace it with the proper size fuse and test the appliance again. If there is power on both sides of the fuse check the Appliance wiring connections at the wire nuts or plug. It’s possible for connections to come loose due to excessive vibration. Correct any loose connections and try the appliance again
If you complete all of these tests and there is 12-volt DC power coming to the appliance, and it still doesn’t come on, chances are the water appliance itself is bad and it will need to be replaced.
Troubleshooting a 12-volt electrical problem in your RV is not that difficult. Follow the logical path of the device you are troubleshooting and see if you can determine where the problem is. It might be possible for you to save your vacation.
Of course if you are travelling through or located near the Dallas Fort Worth Area, you can always drop by our repair shop and have it looked at. To schedule an appointment simply click on the button below.