How to Check the Power Inverter on a Travel Trailer

by Thomas West

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A travel trailer is a self-contained camper designed for long excursions or for short-term living quarters. When parked in a primitive area with no electricity, the trailer’s 12-volt accessories (such as lights and water pump) can operate on a limited basis using the trailer’s battery. However, to keep from damaging these 12-volt accessories, your trailer’s power inverter converts 110-volt AC power to 12-volt DC power when the trailer is connected to an external power source. The power inverter also keeps the trailer’s battery charged when the vehicle is connected to external power or to the tow vehicle. If the inverter is faulty, your accessories will not be able to operate.

Step 1

Locate your trailer’s battery, usually at the front of the trailer on the tongue. Remove the battery cover by loosening the nylon strap and lifting the cover off. Set the cover aside. Disconnect the battery cable from the negative battery terminal by loosening the clamp with an adjustable wrench turned in a counterclockwise direction. Lift the cable from the terminal and push it aside.

Step 2

Connect your trailer to an external power source by plugging the trailer’s heavy black power cable into an electrical receptacle.

Step 3

Operate your 12-volt trailer accessories. Turn the lights on inside the camper. Open a water tap and listen for the water pump to turn on. If all of your accessories are operating as normal, your inverter is functioning normally.

Step 4

Locate the power inverter by checking the owner’s manual for the trailer. Make sure the inverter cooling fan is functioning as this keeps the inverter from overheating.

Step 5

Check the fuses in the fuse box located near the inverter if some accessories are not working. Pull the affected fuse out with a fuse puller and replace it with one of the same amperage if it appears blown.

Step 6

Unplug the trailer from the external power source and stow the power cord. Replace the battery terminal onto the negative terminal and tighten the clamp in a clockwise direction with an adjustable wrench. Replace the battery cover and tighten the nylon holding strap.

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