Pre-trip Refrigerator

Garrity

Member
Feb 6, 2018
90
Arizona
We have a Dometic 3 way fridge in our PUP (sorry I don't have the model). I am wanting to plug into house power to get the fridge cool prior to our trips, then use 12v while in transit. Our PUP has the sink that folds down, and there appears to be switch that turns off power when it is down. I don't know if this just effects the lights, or if it includes everything electrical. Will the sink folded down prevent power from reaching the fridge?
 

generok

Super Active Member
Gold Supporting Member
Feb 7, 2013
3,391
Anchorage, AK
No, it shouldn't. It should just cut power to the roof 12V to prevent the lights being left on when popped down.

You should play around with the fridge some. My Dometic never worked well on 120V, but would freeze water solid on LP mode. The problem I had was mine would not stay lit on LP in transit. Just keep in mind on 12V mode, it will pull some amps. If your TV has a 7 pin plug, and your 12V charge pin is connected, as long as the TV is started, you're sending current to your PUP. If not, you'll be pulling amps solely from the PUP battery.

Honestly, I found that if I cooled the PUP fridge down with it pretty full, it would keep stuff below 40 degrees for up to 6 hours if it wasn't too hot. I ran the 12V mode a couple of times, but never found I really needed to, so I stopped doing it after a couple of trips and never had anything warm when I got to where I was going and could light the fridge again.
 

Dan Wilson

Active Member
Jan 30, 2019
305
Appleton, WI
I agree with generok, good advice. Nothing is more temperamental then a camper fridge. Everybody has a different experience. Some people have found running on the 12v enroute draws down the battery and leaves you vulnerable while boondocking. Others found the propane works enroute while others say their pilot blows out. It doesn't cost much to pack a cooler for peace of mind.
 

erich82

Active Member
Mar 12, 2019
143
...as long as the TV is started, you're sending current to your PUP. If not, you'll be pulling amps solely from the PUP battery.

Are you certain about this? I was under the impression it would pull from both batteries even if the TV is not started (not charging pup battery). I was told not to leave the TV connected with 12V fridge on, as it could kill the TV battery as well.
Does the 7-way power supply shut off if the vehicle is not turned on?
 

erich82

Active Member
Mar 12, 2019
143
I'm not sure if this is the right spot for this, so admin please move if needed.

We have a Dometic 3 way fridge in our PUP (sorry I don't have the model). I am wanting to plug into house power to get the fridge cool prior to our trips, then use 12v while in transit. Our PUP has the sink that folds down, and there appears to be switch that turns off power when it is down. I don't know if this just effects the lights, or if it includes everything electrical. Will the sink folded down prevent power from reaching the fridge?

I think the main reason there is a roof shutoff with roof down is to prevent fire. Those lights can get pretty hot, and rest up against the bed when folded down. Everything else should power though.
 

jmkay1

2004 Fleetwood/Coleman Utah
Oct 10, 2013
7,402
Northern Virginia
I was told not to leave the TV connected with 12V fridge on, as it could kill the TV battery as well.
. This was what I was told as well. You can have a dead car battery if you fail to disconnect the TV. To the OP it should only be the ceiling lights that turn off when galley is in travel mode. The best mode for traveling with the fridge on depends on your fridge.
 

kitphantom

Super Active Member
Platinum Supporting Member
Dec 26, 2009
13,552
Albuquerque, NM
Where a 3-way fridge pulls power from at any given time seems to depend on the refrigerator, camper, and tow vehicle set-up. We've never had a 3-way, but friends do on their Casita. They were warned not to leave it on 12v when stopped for more than something like 15 minutes. They did try to run it on 12v while towing, but discovered their vehicle blew a fuse trying to run the fridge and charge the camper battery on the road. They now tow with on LP, theirs does stay lit. (They need to keep a supply of custom medication frozen, and the bit currently in use below a certain temp, so keeping the fridge at temp is a good thing.)
How well a fridge cools on any setting, and how long it holds the cold is also situational. Ours is a larger fridge, with the freezer having a separate door, so cools very well on either LP or 110, with the help of ice packs in warm weather, esp with sun on that side of the camper. Holding temp on the road varies a lot, but often can get into the unsafe range in an hour or two.
 

GreyFox

Super Active Member
Oct 10, 2018
2,447
S Ontario
I'm not sure if this is the right spot for this, so admin please move if needed.

We have a Dometic 3 way fridge in our PUP (sorry I don't have the model). I am wanting to plug into house power to get the fridge cool prior to our trips, then use 12v while in transit. Our PUP has the sink that folds down, and there appears to be switch that turns off power when it is down. I don't know if this just effects the lights, or if it includes everything electrical. Will the sink folded down prevent power from reaching the fridge?

You have a Dometic RM2193 manual light 3-way gas absorption fridge. To precool it on 120 vac simply plug the trailer into Shore Power and turn the fridge to the 120 vac mode. The galley switch cuts 12 vdc to the ceiling lights and has nothing to do with the fridge. Obey the warning in the owner's manual to run the fridge in just one mode at a time. Also heed the warning to only run the fridge with the trailer leveled, otherwise you can easily destroy the cooling unit.

https://www.scamptrailers.com/images/pdfs/Dometic_Refrig_RM2191_RM2193.pdf
 

MNTCamper

Super Active Member
Jun 14, 2014
1,332
MN
We cool ours down on 120V about a day before we leave and get it loaded up. Because we often leave very early in the morning (on longer trips), we don't even have it running in transit for the first day. This has never been a problem with drives of 8+ hours. Once we get to the first location, we usually end up turning on the propane and running it this way. We run on propane for the duration of the trip usually, including any more driving that we will be doing. As some others have indicated, I find the fridge works best on propane, in fact we often have to be careful about over cooling it. We run it all the time on propane while driving and have never had an issue and it always stays lit.
 

Sneezer

Super Active Member
Aug 8, 2015
2,965
DFW, TX
I plug mine in a couple days before we leave. Since I have the foldover galley that blocks the fridge I have to pop it up before we leave in order to stock the fridge. Most of my trips are only a couple hours away, and I usually flip it to 12V while in transit, and 110V when we hookup at the campsite. I have never bothered with the lpg, although I am going to give it a shot this season.
 

Sjm9911

Super Active Member
May 31, 2018
11,505
Nj
Put some frozen ice water bottles in the fridge while in transit and forget about using the 12v. Not worth it to accadently leave it pluged in and kill the batteries. I read somewhere that some newer tv will automatically isolate the 12 v so the tv will not get drained down.
 

mstrbill

Active Member
Mar 17, 2013
696
Austin , Texas
Does the 7-way power supply shut off if the vehicle is not turned on?
Depends on the brand. The F150SC I had killed the 12V Aux line when the key was off. on GM it's live with the key off. You will have to confirm on your TV.

To precool it on 120 vac simply plug the trailer into Shore Power and turn the fridge to the 120 vac mode.
For a fridge that needs no control power(like a RM2193 model), it's simpler to run an extension cord to the fridge bottom vent and plug the fridge into it.
 

GreyFox

Super Active Member
Oct 10, 2018
2,447
S Ontario
For a fridge that needs no control power(like a RM2193 model), it's simpler to run an extension cord to the fridge bottom vent and plug the fridge into it.

Why is it "simpler" when plugging the trailer itself into Shore Power will send 120 vac to the fridge? [?:~{]
 

Garrity

Member
Feb 6, 2018
90
Arizona
Thank you everyone for the replies. I'll give this a shot for our next trip, Mothers day weekend. I'll skip the 12V option based on your feedback. I haven't been able to get the propane to fire, so I'm going to try clean it out this trip and try again. Thanks also for posting the manual. That should be helpful with the cleaning!
 

Anthony Hitchings

Super Active Member
Silver Supporting Member
Mar 2, 2019
3,530
Oakland, California
Once you crack the propane connection loose it should be easy to take out the frig and thoroughly check all parts and pieces including burner and chimney - which must be free of all blockages and debris
 

erich82

Active Member
Mar 12, 2019
143
Thank you everyone for the replies. I'll give this a shot for our next trip, Mothers day weekend. I'll skip the 12V option based on your feedback. I haven't been able to get the propane to fire, so I'm going to try clean it out this trip and try again. Thanks also for posting the manual. That should be helpful with the cleaning!

Try lighting your stove for a few minutes first. Not sure why, but the dealer told me to try this if I was having problems with lighting the fridge. Might have something to do with air in the lines.
 

silvermickey2002

Morris County, NJ
Sep 11, 2008
4,940
Morris County, NJ
^Yes, I do the same thing! I will light the stove to help get the air out and then light the fridge. Doing this in the dark helps to see the pilot light in the fridge! I find during the day it's tough to see the pilot light.
 

kitphantom

Super Active Member
Platinum Supporting Member
Dec 26, 2009
13,552
Albuquerque, NM
@erich82 We have lit the stove every time we've filled the LP tanks, and often after we've had them off, since we had the pup. That only had the stove and furnace; our small TT has the fridge and hot water tank (electric ignition, so no pilots). Apparently the stove is much less fussy about gas flow and any air in the lines, the openings and flames are much larger than in the other appliances.
We did have the fridge fail to light when we forgot to light the stove a couple of years ago - all the ruined food was a good reminder to not forget again!
 




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