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spegr · 06-24-2011, 02:50 PM

Help, I just bought a 1985 31' Sovereign never owned a Airstream or trailer before....and cant figure out the Dometic Fridge. It's a RM 1303 / Dual Gas/Electric. The guy I bought it off of said it worked.....I dont have the gas turned on, because I dont want to blow myself up..... but it should still work from the electric side right? I dont have the manual....

I have the power hooked up...the green lite is on ....and I've recycled the on/off knob on the bottom and set the thermostat to the "mid" position or a 4. I've left it on all day and the light (12v) I think inside comes on when I open the door but neither the fridge or freezer gets cold and I hear nothing from the back.....running or humming.

ANY suggestions.....a replacement is $1400 big ones.

hutch309.2 · 06-24-2011, 03:20 PM

Hello & welcome new owner.
We all go through the same thing when we buy a used trailer. I would suspect that you will need a new circuit board. I had the same problem years ago and rather than use a Dometic I replaced it with a Dinosaur board. Better price than Dometic.
Dinosaur Electronics
909 NW HWY 101
Lincoln City OR
1-541-994-4344

**DKB_SATX** · 06-24-2011, 04:02 PM

Before you buy the circuit board, see if it cools on gas. If it cools on gas but not on electric, the issue is most likely the electric heating element (but could still be the circuit board, I guess... mine is the primitive kind without the board.)

If it doesn't cool on either one AND the gas flame burns and heats the heat exchanger, it's the ammonia system. If it won't light the gas or heat the electric heating element it's probably the board.

Silver Goose · 06-24-2011, 04:22 PM

Quote:

Originally Posted by spegr

... but neither the fridge or freezer gets cold and I hear nothing from the back.....running or humming.

The absorption cycle type refrigerators don't make any noise. The fridge needs a heat source, either a gas flame or an electric heating element. In most cases the elec element runs on 110 VAC shore power. There are a few out there that have an additional 12 VDC element, but they are rare. The interior bulb is most likely a 12v bulb.

Opening the door and seeing the light only tells me you have 12v going to the fridge and presumably the controller board. Are you plugged into shore power? Are any breakers tripped? Be sure the fridge is set to run on AC and has been on for awhile. Open the exterior hatch behind the fridge and carefully feel the chimney, it can and should be pretty hot. If it's cold, then look for the 110v outlet back there where it's plugged in. If you don't have a meter or outlet tester, plug in a fan or can opener to verify the outlet has power. If not, find the tripped breaker.

If it's hot, but the fridge doesn't cool, the ammonia may have leaked out, look for evidence of corrosion on the pipes in the back. Some describe it as a yellow powder. A replacement cooling unit is an alternative to replacing the whole fridge. Compare prices, you may find a new fridge to be the better deal.

If your outlet has 110 v but the chimney is cold with the fridge turned on (give it a couple of hours), the board is a possibility, or the 110v heating element has burned out. At this point I would try it on gas. Be sure your tank valves are open and that your furnace, water heater and stove light up proving you have purged air from the gas lines. During the ignition cycle you should hear a clicking back there indicating the ignitor is trying to light the burner. You may not be able to easily see the burner flame, but as with the electric, things should get hot after awhile. Again, if the chimney is hot, the fridge should start cooling in a few hours. The back wall of the freezer is what you may feel getting cold first.

If it works on gas but not 110v, then further trouble shooting would be in order to determine if it's the board or the heating element, or just a loose connection.

spegr · 06-24-2011, 08:00 PM

Thanks guy's.......very helpful. I just took a picture....so you can see.

Yes, on the 12v and it's hooked up to electric "shorepower"....haven't tried gas yet. I left it plugged in for 7 hrs and nothing....all CB's are good ON getting power to the fridge.

No on the ammonia coolant smell, or powder.....the PO said he had the circuit board replaced in 2010.

I'm pretty handy I just dont know a thing about the Airstreams yet. My friend said they are cheap to get into, but expensive to get out of.
I just popped open the back and found the red and white wire came loose out of the white plastic connector.....on the bottom rear of the fridge....they were almost falling out of the connector itself.
Now, I know where the red wire came from the far right hole) but DONT know which connector the white 10ga wire (maybe a ground?) came off. I cant pull the white three hole connector out far enough because it appears to be attached to some short wires inside the bottom of the fridge.

Does anybody know where wires these go? I dont have a manual or fridge manual.....I dont want to make sparks and mix gas...how do I turn it on? I'm in the middle of MS and there are no dealers or Airstream Mechanics in Meridian, MS.

Really though, thanks for the inputs I'll go outside and maybe try to pull it out.

Splitrock · 06-24-2011, 08:26 PM

I hope you have the power disconnected before working on that back panel. Those refrigerators aren't unique to Airstreams. There's only a couple manufacturers and they're in about every RV out there. Start calling RV dealers for the location of the brand specific service center.

My refrigerator cooled the freezer on electric but I never tried it on gas. My wife took one look at it and said "no way do we keep that". I have a new one seasoning in my shop while I prepare the interior of the trailer.

I was going to clean mine up and go camping. That was a year ago. I ended up gutting it and replacing all the components. Now I'm installing new floor covering in preparation to building new cabinets, countertops, and installing all new furniture. I had September 1, 2011 as my target finish date but I may have to back that up one year according to my current rate of progress.

Silver Goose · 06-24-2011, 08:37 PM

http://gasrefrigeration.net/dom_techdata/763_1303SM.PDF

Try this link. It is the PDF for your model. It looks like you may have the 12v feature, but that should have nothing to do with why it doesn't work on 110v. Look at fig 5. You may have wires going only to the center and right terminals. They are 12v. Observe polarity. It appears from the diagram that the terminal block in question is how 12v is applied to the board. Don't understand how you get the green light and interior light on though if that wire was off, or was it just loose?

Silver Goose · 06-24-2011, 08:47 PM

Quote:

Originally Posted by spegr

...
I'm pretty handy I just dont know a thing about the Airstreams yet...

As Splitrock said, most of the fixtures and components in an Airstream are off the shelf standard items found in any brand and type of RV. And as always, pull the plug and disconnect the house batteries when making those connections.

TG Twinkie · 06-24-2011, 09:09 PM

Can I assume the fridge is level in both directions?

spegr · 06-24-2011, 09:36 PM

Okay the trailer is level.....no gas even hooked up....I just drove it home and the red wire was barely in the connector but the white wire was touching the aluminum body. I am learning more about gas powered fridges than I care to know. I saw that diagram it is awesome.....ran out and placed wires in the connector....far red/on right....white ground on middle. I have no IGN wire...or can find one.....I'll see if this cools in a hour or so on electric.

It's late so I'll check it tomorrow morning and let you know.....and thanks again.....I would like to save the $1400 for a new dual A/C unit........especially if it I can get the fridge working.

Thanks

spegr · 06-24-2011, 09:37 PM

BTW Splitrock your trailer looks awesome......it hasn't been polished has it?

Splitrock · 06-24-2011, 09:50 PM

Quote:

Originally Posted by spegr

BTW Splitrock your trailer looks awesome......it hasn't been polished has it?

No polish. I washed it last year when I got it. I'll strip it when the interior is done. That may be a year or two from now.

vswingfield · 06-24-2011, 10:07 PM

I replaced my Dometic 1303 a little under 3 years ago. It had lots of problems, including bad door seals, and eventually quit entirely.

Before I gave up on it though, I did find a pdf version of the Dometic Diagnostic Service Manual for the 1303 AES models. I have attached a copy of it. It's pretty though, 93 pages in all. It is heavily illustrated and has good troubleshooting flow charts.

Hope this helps. It should even come in handy if you have someone else check it out.

Best of luck!

Silver Goose · 06-24-2011, 10:25 PM

Quote:

Originally Posted by spegr

.... I have no IGN wire...or can find one....

I believe the function of the IGN wire was to automatically switch the fridge to 12v operation when power was available from the alternator when the engine was running. In the trailer environment, this would require a 9-pin trailer connector.

vswingfield · 06-24-2011, 10:33 PM

Quote:

Originally Posted by YankeeDoodle

I believe the function of the IGN wire was to automatically switch the fridge to 12v operation when power was available from the alternator when the engine was running. In the trailer environment, this would require a 9-pin trailer connector.

The old Dometic 1303 fridges don't operate on 12v, 120 AC or propane only. They only use the 12v to power the circuit board.

Silver Goose · 06-25-2011, 07:37 AM

Quote:

Originally Posted by vswingfield

The old Dometic 1303 fridges don't operate on 12v, 120 AC or propane only. They only use the 12v to power the circuit board.

I agree that most were either never connected to run on 12v and there may have been some sub-models that didn't include the 12v heating element but I had one that did. If you refer to the installation and op guide for the RM1303 I posted a link to earlier in this thread you will see both heating elements are in the chimney assembly. Further down are the wiring directions to enable the 12v operation in either a MH or a TT.

It is rare to find a TT and a TV with a 9-way connector. If the 12v line was simply tied to the house battery circuit, it would run the battery down quickly. Thus the requirement for a high current capable charge line (#8 minimum) and a vehicle ignition sense line for the fridge to operate on 12v. I think the 12v element drew 10A. The TV would require specific wiring for this, so as a practical matter, it was rarely enabled in travel trailers.

**jcanavera** · 06-25-2011, 08:14 AM

I used to own a Hi-Lo trailer that had a 3 way fridge that could operate on 12 volts and used the trailer battery. The battery in turn received charge from the tow vehicle. I used to travel on the road with it in 12 volt mode. It all worked great as long as the tow vehicle Bargman connector and the trailer umbilical made good connection. As those contacts corroded over time, the amperage was reduced. Hi-Lo's were telescopic trailers and the lifting mechanism was 12 volt powered. Nothing was more frustrating than to arrive at a campground and find that the trailer battery was dead due to the fact that the amperage flow was reduced due to dirty connectors. I used to carry a thin metal file that I would use to make the connectors on the tow vehicle and trailer plug "clean" prior to leaving on a trip.

Jack

mimiandrews · 06-25-2011, 09:30 AM

rvmobile.com has great information and schematics on all kinds of RV fridges. They did good work for us when our cooling unit needed rebuilding.

spegr · 06-25-2011, 10:43 AM

Okay nothing......on 110v........the green light is on.....I've recycled the fridge ON/OFF switch more times than I care to admit.......I think the way way to go is find a RM 2820.

This thread is dead.....

Thanks Guys

Shame because it look's great and is very clean.

TG Twinkie · 06-25-2011, 11:16 AM

Have you checked to see if there is 120 volts going to the heating element? If so,and there is; it may be a bad heating element. The element is located in the stack near where the burner is. Look for 2 high temp wires and follow them. A new heating element is a cheap fix. You could wire a heating element directly just to test it and the cooling unit.

Don't give up yet!!!