QuestionI purchased the ground kit and there were trouble shooting instruction included.
I went through the trouble shooting procedures and found that when I checked the DC volts between J4 and J10 with the unit off that there is 13 volts. The documents says there should not be voltage present. I am questioning this since J4 is the 12 volts input and the J10 is Ground so with the unit on or off it seem that there should always be 12 volts.
Is there any way I can test the control board befor I buy a new one ?
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Followup To
Question -
While using Refrigerator in the gas mode it keeps going into check. Sometime it will run all night and sometimes only 10 minutes or so. I have 1994 layton with a Dometic RM2611 prod 9215734343.
Answer -
Barry,
It sounds like a ground problem which can probably be fixed by rewiring it using part # 3108702675. It could also be low DC input voltage or a bad circuit board or bad relighter. I would start with the wiring kit and see if that didn't fix it first though. I hope this helps and good luck.
Darren
AnswerBarry,
I'm not sure why is says that because in the troubleshooting I'm enclosing it clearly says to check for voltage on those 2. Maybe something here will help and again good luck.
INTRODUCTION:
The purpose of this bulletin is to aid the servicer in proper diagnosis and repair of AMES/AES refrigerators. This bulletin will provide the servicer with information to find the hidden variable/s that can cause an erratic check light.
DETAILED TROUBLESHOOTING LIST
DC POWER SUPPLY
Clean direct current DC power is mandatory for high tech circuits to operate as designed. The source for DC power are a battery and a converter.
A battery will provide straight line DC charging Uof the battery by the converter or the alternator.
The converter and alternator produce DC power by a series of diodes that rectify alternating current to DC. A battery or capacitors can be used to clean up the AC ropple that is present after AC voltage has been rectified.
AC ripple can be measured by a voltmeter set on the AC scale at the main terminal block connections. Six volts AC or less is acceptable.See Fig 1
A brief interruption of the DC power supply while refrigerator is operating on gas can cause a check light; for example; Turning the refrigerator OFF- ON while operating in the gas mode can cause a check light. The switching of relays from converter power to battery power when unplugging from shore power or shutting down of the generator could interrupt DC power long enough to cause a check light.
The thermocouple produces 25- 30 MVDC when operating . When DC power is interrupted and restored, the thermocouple may not have sufficient time to cool. If the power module sees above 6 MVDC, when power is restored the power module sees above 6 MVDC, when power is restored the power module will assume a problem in the gas mode and immediately turn on the check light.
GAS SUPPLY
The refrigerator requires 11 inches water column with half of all the BTU's of the RV turned on ( half of all appliances turned on). With all the appliances off, the pressure of the refrigerator should not exceed 12 inches water column. The gas pressure for the refrigerator is taken at the test port after the solenoid with the refrigerator operating.
3. GROUNDS
A. A quick easy way to test for ground problems can be done with a millivolt meter.
1) Connect a millivolt meter to J3 of power module and the negative (-) connection of the main terminal block.
2) Pull one of the wires off the solenoid valve. The millivolt reading should be one or less.
3) Put the wire back on the gas solenoid valve and with the reigniter sparking, the millivolt meter should read 5 millivolt shows more than six a ground problem exist. Proceed to section B.
4) The millivolt meter should register between 25-30 millivolts with gas flame burning.
5) Shut the manual gas cock valve off and watch the millivolt reading as it drops. Note the millivolt reading when the reigniter starts sparking ( 7- 13MV).
B. Relocating Gas Solenoid Ground
1) Clean terminal J3 and J10 on power module.
2) Remove wire from J10 and tighten the terminal with pliers. Do both ends of the wire.
3) Remove white wire from gas solenoid valve and connect to the ground strip.
4) Connect a piece of wire ( 16 gauge minimum with a ring terminal on one end and 1/4" spade connector on the other end ) between the gas solenoid and the ground terminal strip. Place the ring terminal under the screw on ground strip.
5) Reverify Section 3A3.
4. Components
A. The Thermocouple is a component extending above the burner assembly so the tip is in the path of the flame. During normal gas operation, the thermocouple should produce 25 to 30 millivolts when connected to the lower circuit board. Any reading below 18 millivolts could cause erratic gas operation. NOTE: A reading of 18 or less could be caused by low gas pressure or improper thermocouple location. The thermocouple should be centered over the burner and extended over 3 slots.
B. The burner is a horizontal slotted metal tube located below the flue tube of the cooling unit. The burner should be cleaned periodically ( at least once a year). To clean the burner, remove from refrigerator and check for any foreign residue ( rust, spider webs, etc.) that could cause a deflection of the gas flow or flame. Soak the burner in an alcohol based solvent and allow to air dry. Reinstall in refrigerator and leak check all gas connections with an approved leak check solution.
C. The Reigniter is an electronic device that produces high voltage to create a spark at the burner only on gas mode.
Verify proper DC power is at the positive ( +) and ground ( - ) terminals. The reading should be within one volt of the voltage at the main terminal block during the trial for ignition.
D. Electrode
First do a visual check for cracks or breaks on the ceramic insulator. Verify the mounting bracket is attached properly to the electrode. If either of the above is found, replace the electrode. The spark gap must be set at three ssixteenths ( 3/16" ) of an inch and tip of electrode above the slots in the burner.
If reigniter and high voltage cable are good and there is no spark at the tip of the electrode, replace the electrode.
E. The Solenoid Valve receives DC power when the AMES/AES control selects LP gas operation. The solenoid coil opens an internal valve seat and allows gas to follow to the main orifice.
Check the solenoid valve with a properly calibrated ohm meter. Remove one of the connectors from the solenoid and measure the resistance across the terminals. The proper reading would be 44-53 ohms.
Hook a manometer to the test port. With DC power supplied to the solenoid terminals, a gas pressure reading of 11-12 inches of water column should be present. If no pressure or low pressure is present at the test port, the gas solenoid is defective and should be replaced. NOTE: Verify the LP gas system pressure before replacing a valve with low pressure.
F. The Power Module monitors the DC and AC power supplied to the refrigerator. It coordinates the operation between DC, AC and gas in conjunction with the setting of the display panel.
Check the fuse(s) under the cover on the power module for continuity. Replace with same size if bad. Inspect for loose relay and plugf 3 (P3) on the board. If loose, replace board.
When the refrigerator requires additional cooling, the power module will send DC voltage to the solenoid and reigniter. The trial for ignition will last for 45 seconds and at the end of this period the check light will come on.
NOTE: When the thermocouple output is between 7-13 millivolts DC, the DC voltage to the reigniter will be turned off. If the flame is extinguished, the power module will not supply DC power to the reigniter until the millivolts DC drop to 7-13 MVDC. It may take 10-15 seconds for the thermocouple to cool. The PAL Tester will allow for proper testing of the integrity of the upper and lower circuit cards. The PAL Tester is available from your local Dometic parts distributor.
G. Control Panel
1) With the main ON/OFF switch on the control panel in the OFF position: Check for DC voltage at plug 1 (P1) terminal 4 of lower circuit board.
If no voltage, check the fuse condition on lower circuit board. Replace if blown. Check for DC between J4 and J10 on the lower circuit board.
2) With main ON/OFF switch on the control panel in ON position:
Check for DC voltage at P1 terminal 1 of the power module. If no voltage is present, then the switch is faulty and the control panel should be replaced. If DC voltage is present at P1 terminal 1, check for DC voltage on P1
terminal 3 on the power module. If no DC power is present then the power module is faulty and should be replaced.
The only way to test any further requires a special tool that would cost more than the cicuit board.
Darren
