13th Oct 2026
Dometic Americana Won’t Run on AC (Works on Gas): Troubleshooting Flowchart
NO AC, GAS WORKS
Dometic Americana Won’t Run on AC (Works on Gas)
The fridge cools on propane but not when you’re plugged in. Check that it’s in AUTO mode and getting good 120 volts, then follow the power through the 5-amp fuse and lower circuit board to the AC heating element.
Dometic Americana & Americana Plus · RM2351 through RM2862
Fits these models
Different model? These steps are for the models above, from Dometic’s service manual for them. For any other Dometic fridge, ask a tech before you test or order parts.
Before you start
- Safety first. These are live 120V tests and can shock you. Dometic says they should be done by a qualified service technician.
- Where things are. The power cord outlet, lower circuit board, fuses and AC heater leads are behind the lower outside vent, under the protective cover.
- Good AC voltage is 100 to 132 volts. Below 100, the fridge cools less.
- You’ll need a multimeter set to AC volts and ohms. A clamp-on amp meter helps for the last step.
PART A · MODE & SHORE POWER
Is the fridge set to use AC, and is AC there?
STEP 1
Check the mode
AC only works in AUTO mode. Press the AUTO/GAS button to the DOWN position so the AUTO lamp lights. In GAS mode the fridge runs on propane only.
Is the AUTO lamp on?
Switch to AUTO
Press the AUTO/GAS button down. With 120 volts available, the fridge picks AC first.
STEP 2
Measure the outlet
Measure AC volts at the outlet the fridge plugs into, behind the lower vent. The fridge must plug straight into a grounded 3-prong outlet, with no adapters or extension cords.
Is it 100 to 132 volts AC?
Fix the shore power
Check the RV’s breaker for the fridge outlet, any GFCI outlet on that circuit, the outlet itself, and your shore power or generator. Repair the problem, then measure again.
PART B · LOWER CIRCUIT BOARD
AC is at the outlet. Is it getting through the board?
STEP 3
Check the 5-amp AC fuse
Unplug the fridge. Pull the 5-amp AC fuse on the lower circuit board and check it for continuity.
Is the fuse good?
Replace the fuse
Put in a new 5-amp fuse. If it blows again, there’s a short in the heater or its wiring. Test the heater in Step 6 before you put in another fuse.
STEP 4
Measure AC into the board
Plug the fridge back in. Measure AC volts at J5 (black) and J6 (white) on the lower board.
Is it 100 to 132 volts AC?
Fix the cord or wiring
AC is at the outlet but not at the board. Check the power cord and its connections at J5 and J6. Repair them, then measure again.
STEP 5
Measure AC out to the heater
Unplug the thermistor from P2 so the fridge calls for cooling. With it running in AUTO on shore power, measure AC volts at J7 and J8, the heater connections.
Is there 120 volts AC at J7 and J8?
Check the fuses and upper board, then replace the lower board
Check the 3-amp DC fuse, the wire harness and the upper (eyebrow) board. If they’re all good, AC is going into the board but not coming out, so the AC detection circuit is damaged. Replace the lower board. Match the part number on your old board’s label.
Dometic Hercules Board 3316348.900 →OEM board with built-in reigniter. Replaces 3850712013. 
Dinosaur 3850712.01 Board →Aftermarket replacement for 3850712-xxx boards. 
Dinosaur 3850415.01 Board →Replaces 3850415 boards only.PART C · AC HEATING ELEMENT
The board sends power. Is the heater using it?
STEP 6
Test the heating element
Unplug the fridge. Remove the heater leads from J7 and J8 and measure ohms across them, with the heater at room temperature. It should match your model within ±10%:
| Model | Watts | Ohms | Amps |
|---|---|---|---|
| RM2351, RM2354, RM2451, RM2454, RM2551, RM2554 | 175 | 80 | 1.5 |
| RM2652, RM2662, RM2663, RM2852, RM2862 | 325 | 44 | 2.7 |
Is the reading in range?
Replace the AC heating element
An open reading (no continuity) or a reading out of range means the heater has failed. Get the right wattage for your model; never use one that’s bigger or smaller. Have your product number ready and ask a tech if you’re not sure which one you need.
STEP 7
Check the current draw
Reconnect the heater, plug in and run the fridge on AC. Clamp an amp meter around one heater lead. It should draw about 1.5 amps (175W) or 2.7 amps (325W).
Is the heater drawing current?
Check the heater connections
Look for loose, burnt or corroded terminals on the heater leads and at J7 and J8. Repair them and test again.
AC is working
The heater is getting power and drawing current. Plug the thermistor back into P2. If it still cools poorly on AC but fine on gas, check that the voltage stays above 100 under load, and check the venting and leveling.
Still stuck? ask a tech with your model, product number and the readings you got. We’ll confirm the part before you order.
Covers the Dometic Americana and Americana Plus: RM2351, RM2354, RM2451, RM2454, RM2551, RM2554, RM2652, RM2662, RM2663, RM2852 and RM2862. Based on the Dometic RM2xxx service manual, Diagnostic Flow Chart, Symptom 3: No AC operation, operates on gas mode.