Fridge Runs on A/C but not LP

[OBrienP23]

Hello all! I have a Domestic RM2612 in the trailer and our first trip out with this camper will be next weekend. I have run the fridge on electric to make sure it worked and it works fine. However if you unplug the trailer and try and run the fridge on LP nothing happens. There is a click but nothing. And the 'Check' light does not illuminate so at first I thought it was working. Any thoughts? If any more info is needed let me know!

[EMD_Driver]

I pulled up a service manual, that was printed in 1996. That would be the closest year to your 1995 T-2653. I'll paste some of the info below. It will be a good start and we'll keep trying, until we figure out the problem..

"OPERATING MODES

AUTO MODE
Press the AUTO/MANUAL mode selector button to the DOWN position. The AUTO mode indicator lamp will illuminate.

When operating in the AUTO mode, the AUTO mode indicator lamp will illuminate. The control system will automatically select between AC and GAS operation with AC having priority over GAS. If the control system is operating on AC energy and it then becomes unavailable, the system will automatically switch to GAS. As soon as AC becomes available again the control will switch back to AC operation. If 120 volts AC is not available, the control system will automatically switch to GAS operation.
Within 45 seconds the burner should be ignited and operating normally. If unsuccessful, the CHECK indicator lamp will illuminate.

To restart an ignition attempt with the CHECK lamp illuminated or to clear (turn off) the CHECK lamp, press the main power ON/OFF button to the OFF and then to the ON position. The control system will attempt a
new 45 second ignition sequence.

On the initial refrigerator start-up on gas (120 volts AC is not available), it may take longer than 45 seconds to allow air to be purged from the gas line. If the refrigerator has not been used for a long time or the LP tanks have just been refilled, air may be trapped in the supply lines. To purge the air from the lines may require resetting the main power ON/OFF button (1) three or four times. If repeated attempts fail to start the LP gas operation, check to make sure that the LP gas supply tanks are not empty and all manual shutoff valves in the lines are open.

NOTE: DO NOT continue to reset GAS operation if the CHECK indicator lamp continues to be illuminated after 3 or 4 tries.

If 120 volts AC becomes available while the CHECK indicator lamp is on, the control system will switch to 120 volt AC operation, The CHECK lamp will not turn off until the main power ON/OFF button is pressed to the OFF then ON position. In AUTO mode operation, the temperature is controlled by a single temperature setting.

MANUAL MODE
When operating in the MANUAL mode, the AUTO mode indicator lamp (A) will be off, and the refrigerator will run continuously on the energy source selected by the control system.

NOTE: The food in the lower compartment may be frozen if the refrigerator is left on “MANUAL” mode.

STANDBY MODE . .
This control system contains a feature that will continue to operate the cooling system in the event of a failure of a major operating component. If the control cannot read the temperature sensor and operate at the preset
temperature, then the control will run the cooling unit like the MANUAL mode. The refrigerator will continue to operate in this mode indefinitely or until a new sensor is installed and the system is reset."


** After reading and doing everything listed above, see if your flame ignites. If the above instructions don't work, we'll have to check the igniter and it's related components next. It's always best to try the simple things first... If the above does not work, it's going to require the use of some diagnostic tools. First off, would be a volt-ohm meter. If you know how to use one already, that will be a big help.

Please let us know if you still need some help...

[OBrienP23]

Thanks for the quick reply. I have the manual so we have gone through the regular start-up. It does not light after 45 seconds AND the check light does not come on. I have all the test equipment just haven't used it in forever.

[Poppy & Nana]

don't you need a battery for this to run on propane???

[EMD_Driver]

Originally Posted by Poppy & Nana

don't you need a battery for this to run on propane???

I was going to ask that, but he did say it was working on A/C.. But then again..


Do you have a charged 12v battery, for when you are not connected to shore power?

[JohnB]

The fridge needs both 12 VDC and 120 VAC to run on electric. While the element is 120VAC, all the controls are still 12 VDC.

Question: When you go to gas mode, go outside and listen. At 1st thing you should hear a small click of the gas valve. Then it should be snapping none stop about 1 snap per second for that 45 seconds. Trial for ignition is that stage. If there is no non stop sparking snap after the gas valve, it will not start and points to other things.

Confirm it does or does not snap non stop once a second for 45 seconds. If no constant snaping, that is problem no 1.

Also any chance of some pics of the unit outside with the cover off? That will help narrow down what vintage you have. And what year is it?

Hope this helps

John

[OBrienP23]

It has a brand new battery. I'll get some pics today and post them. I'll also listen for the snapping. I can hear the click from inside the camper but no snapping. I'll have my wife turn it on today while I stand outside.

[JohnB]

One simple thing... I thought of this last night after posting. You stated it worked well on electric:

Where you running on electric for a long time, fridge all nice and cooled down and then flip to gas when it did not work?

OR

Was the gas mode tried when the fridge had been off for a bit and then was warmed up?

Reason for asking, the fridge is controled by a T stat. It will only call for cooling if it needs it. If you are running on electric and the frdiege is cooled down to temperature, even if you flip to gas, it will not start to light if there is no call for cooling. The fridge has to warm up inside enough to create a signal to cool regardless if on electric or gas.

I'll have my wife turn it on today while I stand outside.

That is a perfect test, now your are right there and will not miss what happens when. It can be real hard some times to hear all this in the camper.

If you go out and check tonight, assuming the fridge was off for a while now, then turn it on on gas mode and it should try to start after a little bit of pressing the button.

A slight "click" of the gas valve you should hear and then snap,snap,snap non stop on about 1 second intervals for about 45 seconds. You can even put your hand on the gas valve and feel the vibration of the click of the gas solenoid valve come on. It will only be a second click but you can feel it. No click of the gas valve and that means it is not even trying to start. The gas valve and the igniter both use the same signal.

Then pending the vintage of control board after the 1st 45 seconds, it will wait to clear any un-used gas (foggy memory recalls 2 minutes) then it will go back into trail for ignigition for 45 seconds of gas valve on, then 45 seconds of snap,snap, snap.

It will try to light for 3 times (3 sets of 45 sec snap and 2 minute wait,) then go off on saftey and throw a fault light. Add all that can add up and it can be 45 x 3 = 135 sec or 2.25 min. + 4 min of wait to purge = 6.25 min approx from the 1st click until it goes out on saftey and sends the fault light. The fault light is not quick.

Another question: Is this the 1st time for you to ever tried the fridge on gas since you owned it? Trying to sort out if this is a problem that was working and now not or it has never worked since you aquired your sunny.

Hope all this helps and good luck.

PS the gas valve on some of the fridges have a screw driver slot shut off vavle for the gas. The screw driver slot is the direction of flow. Make sure the valve is open. This will not stop the click of the valve, it will click valve on or off, however the gas will not flow with the valve off.

Not the greatest pic to see it, but the screw driver slot is in the middle of the brass valve on this vintage.

[jim44646]

Light the stove to make sure you have a gas supply. Sometimes turning the gas valve on to fast trips the excess flow protection in the line. Turn valve off and wait abit then turn valve on slowly

[OBrienP23]

First, thanks for all the great ideas.

1) I tried starting the fridge on gas when it had been completely off and the door had been ajar for weeks. So it was definitely warm to start.

2) I have gas to all the appliances. Stove works, furnace works, hot water tank works.

I didn't know about the thermal fuse under the shrink wrap or the one reset. I only knew about the two glass fuse on the left hand side after you open the access panel.

When the fridge is started we hear one good click but no, "rat tat tat tat tat...." Like it is trying to light.

[JohnB]

How electrically handy are you?

The click you heard, do you know it was the gas valve? That tells a lot as if it is, then the PC board is sending the signal. The same signal (wire) powers the gas valve and the ignighter so they both have power at the same time. However they both have separate ground wire runs

The first step is to make sure all the grounds are making good contact. It may be as simple as that.

Page 10 in this service manual talks about how to test the ignighter for your model number. And the cable to the electrode. It also talks about the voltage check on the gas valve yellow wire to make sure power is going to the valve.

http://gasrefrigeration.net/dom_tech...121_2852SM.PDF

This is more of a process of elimination trouble shooting. You are going to need a volt/ohm meter and be semi friendly with how to use it.

Once you get into it we can help more if you feel comfortable doing this type of trouble shooting. There is some risk involved, however if you know 120 vac electricity and how to safely work on it, this is not that bad to trouble shoot. The key is know what it is suppose to do so you can back into what is and is not working.

Hope this helps. Glad to type more as needed.

John

PS. My fridge has had the Dometic recall done to it. The thermal fuse and thermal disk switch was part of the recall. Yours may or may not have it. Again pics could tell us and you if it has been done on your unit. With the model/serial number you can look up on the Dometic web site to see if yours is in the recall. It is a free recall can be done by any Dometic service center/RV dealer.

[EMD_Driver]

Here's some more from the service manual.. In reference to the igniter. You said that you don't hear it sparking, so this may be of help... Please note that there can be very high voltage present at the igniter. Always turn the unit completely off, before disconnecting any wiring! Since you will be working at the back of the unit anyway, you can also disconnect the incoming 12v power supply.

"IGNITER
First verify proper voltage at the positive (+) and ground (-) terminals of
the igniter. The reading should be within one volt of incoming voltage at
the main terminal block during trial-for-ignition



Next, remove high voltage cable from igniter. The igniter should produce
a sparking sound, during trial-for-ianition. If not, replace the igniter.


The igniter installed on the refrigerators as original equipment is part
number 2931132019 (RV Gas Model 679). This igniter is rated 50 MA.
This igniter may also be used on any other model.
DO NOT install the Channel Mark 6, Model 12E igniter (shown below) as a service replacement part.


HIGH VOLTAGE CABLE
Disconnect high voltage cable from electrode. If sparking starts during trial-for-ignition, the cable is good. If there is no sparking during trial-for-ignition ' disconnect high voltage cable at the igniter. If there is a sparking sound from the igniter during trial-for-ignition, then replace high voltage cable.


ELECTRODE
Do a visual check for cracks or breaks on the ceramic insulator. The spark gap must be set at three sixteenths (3/16”) of an inch and tip of electrode above the slots in the burner."

[underdog]

Mine had the same issue and probably one reason I got such a deal on the trailer. Diagnosed with help from here.

http://www.sunlineclub.com/forums/f7...ing-14139.html

Bottom line is no clicky clicky and blinking light, it's most likely the ignitor. Found one online for 35 bucks and now works perfect. I think this must be a common problem cause I see lots of posts. Mine looked to have been changed before also.

[OBrienP23]

I haven't started testing with a meter yet. I did notice something strange today. My LP works for all other applicances, I did notice today one tank is near empty and the other is half full. Well this whole time when I try to start the fridge on LP I get the one loud click but not of the click-click-click-click for 45 seconds when it tries to light. BUT the check light has NEVER come one.

Today after I turned both LP tanks off and removed them from the camper for the hell of it I tried it to see what it would do with no LP source. It did the same thing obviously and wouldn't start BUT this time the check light DID light up.

Not sure what that means. I'll be running the meter over everything in the morning.

[OBrienP23]

And of course, with my luck. I just went to switch the fridge back to AC and it apparently does not work on AC either anymore. So I guess I am REALLY going to have to go through everything. I ran the fridge on AC when we first got it and it worked great, this was a couple months ago. So when I was testing the fridge's gas operation I never double check that the electric was still working. UGGGGGH

[OBrienP23]

It is not working on AC either now.

[EMD_Driver]

Just out of curiosity.. Between the time it last worked on A/C and now, have you noticed any yellow powder in the back of the unit? Any ammonia odor?

[OBrienP23]

No and no. Haven't had either one .

[EMD_Driver]

Originally Posted by OBrienP23

No and no. Haven't had either one .

That's good.. Those would indicate a bad cooling unit.

There is an electric heating element, that uses A/C power to heat the coolant and cause it to circulate. The same way that the propane does. Given the age of your fridge, it is possible that both the A/C heating element and the burner assembly/igniter could be bad. The common thing between the two, is the control board. It controls both.

JohnB is much better at troubleshooting and he will not give up, until you have an operational fridge.

I do know that if I can get a 1985 vintage Norcold fridge working on both A/C and LP, after sitting for 15 years, you'll be able to get yours working too!

[EMD_Driver]

Did you happen to download the service manual, that I have been referencing from? If not, you can find it HERE It may help you do some of your own troubleshooting...

BTW: If you didn't already know, HERE is a youtube video that explains how these fridges work...

Here is a reference picture also...