2-way refrigerator operation without a battery

[DieselBurps]

I have a basic question I can not find the answer to.

I have a Dometic 2 way fridge (propane/120volt) in a 1985 Airstream. I can not get the fridge to run on either 120 volts or gas.

I do not have a battery at this time.(I am on shore power)

Do I need a battery to run the fridge even though I am hooked up to shore power?

Is the battery required in order to "complete the circuit"?

I assumed since I am on shore power the fridge should work either way even though I do not have a battery.

[ItsyRV]

DieselBurps wrote:
I have a basic question I can not find the answer to.

I have a Dometic 2 way fridge (propane/120volt) in a 1985 Airstream. I can not get the fridge to run on either 120 volts or gas.

I do not have a battery at this time.(I am on shore power)

Do I need a battery to run the fridge even though I am hooked up to shore power?

Is the battery required in order to "complete the circuit"?

I assumed since I am on shore power the fridge should work either way even though I do not have a battery.

An important think to consider is what was (as in OEM), may not be what is (as in changes over the years). As a result, you'll need to do a bit of looking as it could be a simple fix.

Let me give you an example. My refrigerator needs 12 volts to operate the control functions. It needs standard AC power or propane to cool down. If you read the specs and owner manual and refrigerator manual, removing the battery would not cause an issue with the control function while on shore power as the converter supplies it. BUT, over the years an issue arose that required abandoning the converter 12 volt circuit to the refrigerator, water pump and furnace. In it's place is a fuse block connected to the coaches' battery setup.

What that means is when the battery is removed, I must still connect all the positive cable together and all the negative cables together in order to complete the circuit. My point is no amount of what the refrig supposed to do or what the converter supposed to do or what is this or that matters since its nothing but connecting two cables together to make the circuit. The manuals wont show that. In my case, all a person has to do is look at what was (battery in place with all terminals bridged together) when thigs worked compared to what is when stuff stopped working (cables not together without battery) to see it's just a modification over the last 25+ years.

[dougrainer]

BFL13 wrote:
Thanks for the ideas! I already had the episode where the back outside was hot on 120 but the fridge stayed warm. Turned out to be not level enough. This little fridge is very fussy about levelling, moreso than the taller fridges in our other RVs.

I have a Kill-A-Watt, which I used to tell if there was any draw from the fridge when on 120v, but no convenient way to leave in as a display. I like the indicator lamp idea.

Can't hear any flame. You have to stand on a chair to raise the outside panel, and unscrew the metal cover over the burner to see the flame. PITA. I need to work on a shade for the reflector so you can see if it is lit up when it is not dark in the camper.

The OLD Instamatic refers from the 70's and very early 80's, had to be almost perfectly level to cool correctly. What may look like level enough may be out of level enough to slow good cooling. Doug

[BFL13]

Thanks for the ideas! I already had the episode where the back outside was hot on 120 but the fridge stayed warm. Turned out to be not level enough. This little fridge is very fussy about levelling, moreso than the taller fridges in our other RVs.

I have a Kill-A-Watt, which I used to tell if there was any draw from the fridge when on 120v, but no convenient way to leave in as a display. I like the indicator lamp idea.

Can't hear any flame. You have to stand on a chair to raise the outside panel, and unscrew the metal cover over the burner to see the flame. PITA. I need to work on a shade for the reflector so you can see if it is lit up when it is not dark in the camper.

[dougrainer]

On a Dometic, the only way is to either test for hot on the cover or buy a clamp on AMP meter and test for the amp draw at the wires of the Heat Element. Doug

ANOTHER WAY----- Buy a CHEAP 120 non digital clock and wire it thru one of the 120 Heat element wires. When on 120, the second hand will be turning. I guess you could do the same with a 120 digital, it would then flash when 120 was supplied.

SORRY, Another easier way is to but a standard 120 volt small round LED light and install in the RV by the refer. Wire it thru one of the 120 element wires and when on 120 that LED light would be ON. Doug

Like this, Just need one tho. BUT will only show that the element HAS 120 volts, not if it is Heating

https://www.amazon.com/YC-9WRT-1R-120-10-INDICATOR-MINIATURE-PILOT-LIGHT/dp/B01E2UITTC/ref=sr_1_115?...

[2oldman]

BFL13 wrote:
The gas mode has that reflector but you can't see it unless it is dark, which is not so useful either when you can't see if it lit or not except by going outside.

I can hear mine.

[BFL13]

dougrainer wrote:

BFL13 wrote:
OP is missing in action. 😞

He said he has a two way in his 1985 but standard for 1985 is three way so we still don't know his model.

I missed the part where it can be a three-way but still not need 12v. I get that now. BTW, the 2410 in our 1991 truck camper has that two button system for lighting it, and does not have indicator lights. I did not realize that means it does not need 12v connected--interesting!

Since the OP stated 2 way, I stated NO 12 volts for the RM 100. IF you have a 3 way RM 100, then you DO need a heavy Gauge 12 volt wire Positive and Negative. Doug

Yes, but I think the point is ? that you can have a 12v mode but still no 12v controls, so you don't need 12v except for the 12v mode. Wrong?

Since you are here to ask while I can, is there a clever way to know if the 2410 is on electric ok without having to go outside and feel it? The gas mode has that reflector but you can't see it unless it is dark, which is not so useful either when you can't see if it lit or not except by going outside.

[dougrainer]

BFL13 wrote:
OP is missing in action. 😞

He said he has a two way in his 1985 but standard for 1985 is three way so we still don't know his model.

I missed the part where it can be a three-way but still not need 12v. I get that now. BTW, the 2410 in our 1991 truck camper has that two button system for lighting it, and does not have indicator lights. I did not realize that means it does not need 12v connected--interesting!

Since the OP stated 2 way, I stated NO 12 volts for the RM 100. IF you have a 3 way RM 100, then you DO need a heavy Gauge 12 volt wire Positive and Negative. Doug

[BFL13]

OP is missing in action. 😞

He said he has a two way in his 1985 but standard for 1985 is three way so we still don't know his model.

I missed the part where it can be a three-way but still not need 12v. I get that now. BTW, the 2410 in our 1991 truck camper has that two button system for lighting it, and does not have indicator lights. I did not realize that means it does not need 12v connected--interesting!

[2oldman]

dougrainer wrote:
That is why it is important for the OP to state MODEL NUMBER. Doug

We can hope.

[dougrainer]

BFL13 wrote:
1985 Airsteam TTs had a RM 1303 3-way fridge as standard

https://www.airstream.com/owners/document-archive/product/tt/year/1985/

http://bryantrv.com/docs2/docs/rm1303.pdf

EDIT--using that link above, I went back as far as 1971 and they had "gas/electric combination" fridges as standard. Don't know the model for the fridge.

EDIT--the 1982s still say gas/electric combo, the 1983 says RM100.

seems to be a 3-way that uses 12v

http://bryantrv.com/docs2/docs/rm100parts.pdf

Ref here to a 1976 RM100 in an Airstream

https://www.airforums.com/forums/f425/1976-dometic-rm100-no-cooling-l-kie-what-i-found-106531.html

So that is 1976 for a "gas/electric combo" that was an RM 100 that does need 12v. Still don't have when that "modern" type of fridge started being made for Rvs

1303 is AES and DOES require 12 volt for operation
RM-100 is the old very good standard Dometic non battery model. DOES NOT REQUIRE 12 VOLTS TO OPERATE.

That is why it is important for the OP to state MODEL NUMBER. Doug

[wa8yxm]

There are converters and converters on an older model he might have a Magnetek and those will NOT operate the Fridge without a battery. or a Battery Simulator.. And yes I know why but I'd rather not type it out just now.

Newer well filtered converters like my Progressive Dynamics WILL but the old Magnatek and ones like it will not.

[BFL13]

1985 Airsteam TTs had a RM 1303 3-way fridge as standard

https://www.airstream.com/owners/document-archive/product/tt/year/1985/

http://bryantrv.com/docs2/docs/rm1303.pdf

EDIT--using that link above, I went back as far as 1971 and they had "gas/electric combination" fridges as standard. Don't know the model for the fridge.

EDIT--the 1982s still say gas/electric combo, the 1983 says RM100.

seems to be a 3-way that uses 12v

http://bryantrv.com/docs2/docs/rm100parts.pdf

Ref here to a 1976 RM100 in an Airstream

https://www.airforums.com/forums/f425/1976-dometic-rm100-no-cooling-l-kie-what-i-found-106531.html

So that is 1976 for a "gas/electric combo" that was an RM 100 that does need 12v. Still don't have when that "modern" type of fridge started being made for Rvs

[RLS7201]

MrWizard wrote:

RLS7201 wrote:
1985 is probably stand alone propane, just like a home water heater. No 12 volt required.

Richard

Your thinking 1970's and earlier
By 1985 everything had electric ignition and 12vdc control boards

NO! I was thinking the 80s.
As per Doug's post.

vintage 1985 is just when Dometic came out with the AES model refers. AES stands for Auto Energy Select. They had a an ON /OFF switch with an indicator light. MANUAL Dometic Models, you had to HOLD the Pilot button and then continually push a Manual Piezo lighter button. If the OP has just an ON OFF switch, then he has an AES and requires a 12 volt source to operate. If he has to push in a button and then continually push the LIGHTER button, he does not need a 12 volt source. AS always, MODEL is required to correctly answer his question. Doug

Richard

[BFL13]

Old-Biscuit wrote:
Why reinvent the wheel.....just put a cheap 12V battery in and be done with it

Simple.........

He does not need a battery while on shore power,and if he had one, it would need recharging/maintaining, and he has that old converter that is likely to do a poor job of that if it even works now.

For the cost of a new battery, he can have that new converter I linked and have no converter issues and no battery to worry about either.