By Neal Weber
Many of the Dometic refrigerators have a heat strip in the door frame at the top of the refrigerator section. This is intended to reduce the formation of condensation and wetting the seal — but the strips draw 12 watts of battery power when the refrigerator is turned on.
Some Dometic models have a semi-hidden switch to disable this, but many of the models like mine (DM2652LBX) don’t. The strip is wired in parallel with the interior light circuit. Others have snipped the wire behind the light. Since I camp fairly often in damp environments, I like to have a functional heater when on shore power.
There’s an easy solution to the issue — the heater and interior light are wired to the circuit board in back of the fridge through a single spade lug connector. I just disconnect the connection when I’m going to dry camp for more than two nights. This provides an additional benefit: disabling the interior light, keeping the refrigerator 12-volt power draw to an absolute minimum.
1. Open the exterior refrigerator access cover. Locate the wiring diagram. The diagram on mine is pasted to the burner cover. Disconnect the 120-volt power before proceeding.
2. Find the control board. It is usually under a black cover on the left side of the unit. To remove the cover, loosen the screw on the top and then use a screwdriver in the slots on the side to pop the tabs loose. Be careful not to break any wires or the cover.
3. On the wiring diagram, locate the interior bulb and climate control heating element (not the 120-volt heating element or the fridge won’t cool!) Mine was the one connected to terminal #2. (This is where the screwdriver is pointing in the picture.)
4. Disconnect the spade lug and put it somewhere where it won’t short anything out.
4.a. Optional: Put an SPST switch in-line between the spade connector and the circuit board.
5. Close up the control board cover and restore 120-volt power to the unit. Turn the refrigerator on and make sure the bulb is dark and the area where the strip is doesn’t get warm.
6. Close up the exterior hatch. Make sure the drain hose is routed to the proper place.
Doing this modification reduced the refrigerator draw on my batteries from 1.6 amps to 0.6 amp when the gas valve is open, and 0.2 amp when it is closed. This modifcation saves 24 amp-hours per day when dry camping!