Thanks for the advice, as said we are new to this.
Originally posted in the general section (i think it was the general section) and got advised to post here, so here goes.
We have a dometic fridge RM 2350 that works fine on Gas and 240v, BUT, when travelling looses the cold.
We start off with it well chilled, plugged in overnight, put in stuff from the fridge, but it does not stay cold when travelling.
Purchased a thermometer that has a read out outside of unit, so do not have to open door to check. Have had new plug fitted to van, even have a different tow vehicle, had all checked by Dometic agent and they say it is working on 12v.
Any body have a similar problem or any idea what to do next ?
Could it be the seal ? Has anyone ever replaced a seal on the door ?
-- Edited by Howards on Thursday 9th of January 2014 02:40:05 PM
It's more likely to be a voltage drop problem related to the circuitry from the tow vehicle. It is imperative that wiring for the 12v part of the fridge is of sufficient gauge to limit voltage drop to less than 3%. Depending on the size of the fridge, and therefore the size of the 12v element in the fridge, wire size for just running the fridge could be anywhere from 8mm2 to 13mm2. Connections also need to be perfect.
Had my 3 way fridge for 8 years. (I travel fulltime) It never got cold when travelling on 12 volt. Had it checked several times. all was ok. they said !!.
Had a problem with my breakaway brakes last week. Decided to check wiring on 12 pin plug between van and tug. Guess what ??. Wiring was incorrect. Fixed it myself AND fridge works perfectly on 12 volt now. You just cannot trust other tradesman.
HI
Easy way to check for voltage drop if you have a multimeter or a friend who has one
[1] make sure ALL 240V power is turned OFF
[2]Gain Acces to rear of fridge [bottom ]
[3 you should see where the 12V power is connected[two heavy cables]
[4]set meter[ if required] to a range just above 15V DC
[5]connect meter lead to the12V terminals
[6] turn fridge to 12V operation & thermostat at max cool
[7]Connect van to vehicle start engine & run at FAST idle ,take meter reading
[8] run engine at a faster rate,read meter , If the volts are encreasing, wait until they stabilize should be no more than about 10m
][9]post readings here
As other people have commented; they don't really work well off 12v when travelling anyway! We have a M/H (i.e. no trailer hook ups or anything) and the fridge doesn't work well on 12v when travelling. It works brilliant on 240v and Gas when stopped but barely keeps cold when travelling. We've had it all tested and all is OK it's just that it keeps things from going stale but not cold. We have had modifications done to our fridge (extra vents and flue) and still no good. The answer? Whenever we stop for half an hour or more, it goes onto gas and this sorts it out!
PS It really struggled yesterday in 46 degrees regardless of the power source!
As other people have commented; they don't really work well off 12v when travelling anyway! We have a M/H (i.e. no trailer hook ups or anything) and the fridge doesn't work well on 12v when travelling. It works brilliant on 240v and Gas when stopped but barely keeps cold when travelling. We've had it all tested and all is OK it's just that it keeps things from going stale but not cold. We have had modifications done to our fridge (extra vents and flue) and still no good. The answer? Whenever we stop for half an hour or more, it goes onto gas and this sorts it out!
PS It really struggled yesterday in 46 degrees regardless of the power source!
HI
No model number ,so I do not know what the element ratings[Watts] are for 240V & 12V ??
But IF the elements RATINGS are the same or near the same I would suggest you are not getting a good 12V+ at the fridge 12V input when on 12V!!
Undersized WIRING !!???
Check that you have in excess of 12 V with the engine running at fast idle ,AFTER the batteries have been topped up !!.
You should actually be getting around 13V if the wiring is realy good
Our Evernew had issues from day one which was wired from the 12 pin flat plug and I ended up using a dedicated Anderson plug direct wired from my tug aux battery to the the fridge/freezer (184 litre). Since doing it, it works (almost) as good as when on LPG. Just my experience so hope it helps.
__________________
Cheers Jeff
Ticking off the bucket list before we kick it!
200 TTD with Evernew 22'6" and 40+ years in the oil & gas industry, now retired. CMCA Member.
Thanks to everyone who has replied, we are organising to borrow a multimeter so will check the voltage as suggested. We have been caught up on Grandparent duties (school hols ) so appologies for slow response to everyone. Thanks again to all.
HI Easy way to check for voltage drop if you have a multimeter or a friend who has one [1] make sure ALL 240V power is turned OFF [2]Gain Acces to rear of fridge [bottom ] [3 you should see where the 12V power is connected[two heavy cables] [4]set meter[ if required] to a range just above 15V DC [5]connect meter lead to the12V terminals [6] turn fridge to 12V operation & thermostat at max cool [7]Connect van to vehicle start engine & run at FAST idle ,take meter reading [8] run engine at a faster rate,read meter , If the volts are encreasing, wait until they stabilize should be no more than about 10m ][9]post readings here
PeterQ
Hi hit reply and entered readings, but not sure if was supposed to use this way, very new at this
plugged into car ( 2nd battery ) engine not switched on 10.3v
OK, next question..Is the 2nd battery connected directly to the start battery?
The reason that I ask is that the voltage from that second battery is extremely low on your first reading with the motor off and it doesn't get a whole lot better when the motor is running.
If you have a VSR between the start and 2nd batteries, was it in the on condition when you took those later readimgs?
dont know will have to check how all connected What is VSR ?
HI
VSR = "'voltage sensitive relay"
The BASIC operations are"
connect the two batterries together when the Crank battery reaches aroung 13+volts
Disconnects the batteries from each other,when / if the voltage drops to around 12.6V
Protects the Crank battery from being discharged by loads on the 2nd battery but allows the 2nd battery to recive some charge charge when voltage is above the cutout volttage
Fom those readings I would say for a start you have one very sick battery [2nd battery]
I would also say you have a problem in the charging circuit,poor connections , bad jonts or seriouslyundersized cables
Do not just replace the 2nd battery until the charging problem is rectified!!
To check they charging circuit [ again with engine running at fast idle & fridge on]
[1]Check the voltage at the CRANK battery ,directly on the lead terminal posts
[2]Check the voltage on the terminal connectors
Both readings should be virtually the same
[3]connect a long cable to the pos probe of the meter
Test voltage between the lead pos posts of both batterries,
[4] repeat between NEG posts of both batterries
Post readings
PeterQ
-- Edited by oldtrack123 on Thursday 16th of January 2014 12:33:26 AM
Yes have to start at the beginning
What tug are you using
Some of the later models will not charge a second battery by the usual methods due to computerised alternators
I personally run a dc dc charger in a late model prado
If the charging circuit is ok next to check is the wiring from the secon battery right through to the fridge
This should be 6mm paired wiring and nothing less
This will ensure practically no voltage drop as you have
have all this in place and you will be ok
Your problem is most definitely the low voltage caused by either the charging of your second battery, not the correct thickness of wiring or a combination of both
Good luck and let us know of the outcome
