Electrical Anderson Plug Straight To Fridge?

[Kanocg]

Hi all,

Long time caravan lover, short time member, first time poster.

I have a 2016 18.58-2 Pop Top Expanda Outback with the Thetford N3185 174 L Fridge.

We bought it back at the start of March 2020, and, thanks to Covid, have barely used it.

On the few trips we have managed to take it further than the front gate, I've become aware that the fridge will only last approx. 20 mins, then will start to flash battery.

We have dual 110AH AGM, and van is connected to car via 12 pin plug. Tug is 2019 Ford Everest Trend 2L Bi Turbo.

We are now planning a larger 2 month trip through central Aus, so I need to get this sorted ASAP.

What I'm wanting to know is if my planned setup will work to keep the fridge running at all times:

1) Run a new Anderson plug kit from battery to back of car. Kit will come from battery and be fused under bonnet. Still looking at if I need a relay or not.
2) Connect 8AWG cable at base of fridge where cables are currently feeding fridge(access via hatch on outside of van)
3) Run 8AWG wires through box chassis, following existing cables, bring out of grommet near hitch.
4) Fit off Anderson plug to this cable, ready for connection to tow car.

My limited understanding is that this will keep the fridge running off the tug battery while alternator is running, meaning the fridge should run whenever driving.

Can one of you smarter people please confirm this will work, or let me know where I need to run?

Alternatively, I'm open to other suggestions.

Should I run Anderson plug to battery charger in van?

Thanks in advance for your help.

Kano.

 

[Boots in Action]

Hi all,

Long time caravan lover, short time member, first time poster.

I have a 2016 18.58-2 Pop Top Expanda Outback with the Thetford N3185 174 L Fridge.

We bought it back at the start of March 2020, and, thanks to Covid, have barely used it.

On the few trips we have managed to take it further than the front gate, I've become aware that the fridge will only last approx. 20 mins, then will start to flash battery.

We have dual 110AH AGM, and van is connected to car via 12 pin plug. Tug is 2019 Ford Everest Trend 2L Bi Turbo.

We are now planning a larger 2 month trip through central Aus, so I need to get this sorted ASAP.

What I'm wanting to know is if my planned setup will work to keep the fridge running at all times:

1) Run a new Anderson plug kit from battery to back of car. Kit will come from battery and be fused under bonnet. Still looking at if I need a relay or not.
2) Connect 8AWG cable at base of fridge where cables are currently feeding fridge(access via hatch on outside of van)
3) Run 8AWG wires through box chassis, following existing cables, bring out of grommet near hitch.
4) Fit off Anderson plug to this cable, ready for connection to tow car.

My limited understanding is that this will keep the fridge running off the tug battery while alternator is running, meaning the fridge should run whenever driving.

Can one of you smarter people please confirm this will work, or let me know where I need to run?

Alternatively, I'm open to other suggestions.

Should I run Anderson plug to battery charger in van?

Thanks in advance for your help.

Kano.

hi @Kanocg , the fact that the AES is flashing after just a short run may indicate that battery voltage is below par and charging may not be up to speed whilst driving. There could be plenty of other reasons that other members more familiar with that type of fridge and its operation will advise you about. However, modern alternators in the latest tugs do NOT put out sufficient voltage to charge van or auxiliary batteries and may necessitate you installing a DC to DC charger to get sufficient charging voltage from tug to van batteries and to operate the fridge properly whilst driving. The following attachments from RedArc may be helpful to you.

 

[Drover]

As Boots said plus....................... 12 pin set ups are often inadequate and in most Fords the alternator is Smart so causes all manner of drama by dropping the voltage and thusly not enough juice for fridge ..... The Thetford is a 3 way fridge so doesn't/cannot run off the van battery .........

............ Your plan sounds like a good one but being a Ford it probably has a smart alternator and the way they set it up will determine where you tap your cable some have a load sensor on the Neg, some on the Pos, I think on Fords you hook direct to POS terminal and follow the NEG battery lead to the chassis ground and tap in there as the sensor is on the NEG terminal, then the smart alternator will see the load and keep up the power and not go to sleep .... A direct hook up to battery the alternator doesn't see any drain/load so goes to sleep, that is why a lot of dead batteries happen because folk tap in wrong , mates Ranger went thru a couple of batteries until it was realized they had done the hook up for his DC-DC wrong .....

On the fridge end of your 8 B&S cable fit an anderson which can marry up to an Anderson (smaller cable pins) on the 12v fridge leads, I would fit the fridge switch here, this anderson set up gives you a good connection for your fridge with no loss, you can also tap the D+ lead to it as well ( it tells the fridge that 12v is connected so it will fire up on 12v) at present it probably picks up from 12 pin........ leave your 12 pin set up as is and just disconnect the 12v supply at the fridge, then any other stuff that runs off that circuit will be happy....... No matter what set up you go, the D+ lead must be hooked up to the tug 12v or your fridge won't operate on 12v, its not to be confused with the 12v supply from van battery for the fridge controller.... There are 3 12v supplies to fridge.

If you are planning on fitting an aux battery in tug I would fit a DC-DC charger, I like the Cetek D250S myself, in the tug to charge the battery and hook the van fridge to it, the Cetek allows you to draw power from the tug when engine is running and also plug in a solar panel ............... This would also allow 12v from tug to charge van batteries but if you have solar on van its not really needed......... I only have power to fridge from tug and actually have no way to charge van batteries from tug at all, in fact I have forgotten to make sure the auto button was pressed on fridge so it spent a few hours shut down and fridge temp rose a few degrees on a hot day....

Thetfords do require a certain start sequence to get them going properly on 12v so make sure you have a good read of the manual, recall someone having some drama getting his to work once.



If you have a stop/start set up in the tug it may need to be looked at differently.

 

[millers]

Hi @Kanocg,
A few things to have a look at.
The N3185, I believe is auto source and can be configured to be 240V, Gas or 12V. So the flashing of 12V may mean that it is not getting 12V for cooling.

The other is the set up. This fridge has 2 12V connections. The 1st is a low current draw for the control of the fridge. This is usually of the caravan batteries and is required to control the fridge in all modes (gas lighting, relays etc). The 2nd connection is the cooling system and is the high current draw. This is usually of the tug as described above (@Boots in Action).

It is possible to run the high current from the caravan batteries, but not recommended as it will flatten them quickly. Better to switch to gas or 240V.

 

[Middo]

We have a ford everest and fitted a voltage sensitive relay in front of the battery. Made a bracket to support it out of aluminium bar from Bunnings. Negative wire has to be connected to the chassis. Taped the bracket up so there was no edges for the cable to rub on. With the relay, set and forget is best and you don’t have to worry about flattening the battery. Attached photo of where it is just in front of the battery

 

[Boots in Action]

We have a ford everest and fitted a voltage sensitive relay in front of the battery. Made a bracket to support it out of aluminium bar from Bunnings. Negative wire has to be connected to the chassis. Taped the bracket up so there was no edges for the cable to rub on. With the relay, set and forget is best and you don’t have to worry about flattening the battery. Attached photo of where it is just in front of the battery

Hi @Middo , I am with you on having a VSR (voltage sensitive relay), mine is a Projecta 100 amp type. Specs indicate that "cut in" is at 13.4 volts and "cut out" is at 12.8 volts. So when 13.4 volts is reached with alternator or tug battery voltage, the relay closes and connects circuit to van fridge or any other accessories on that line. When voltage drops below 12.8 volts, (when engine off or very heavy electrical load?) , then relay opens and disconnects the power to the fridge and other electrical devices on that line.
However, just to clarify the electrical side of a VSR. There are only two connections involved- "Main" (which connects to the tug starting battery Positive terminal), and "AUX" which connects to the accessories on that line including fridge. The remaining thin black wire is the earth return for the voltage sensing coil and the LED light - both low current devices. This thin black wire must be attached (connected) to the vehicle body, not just to a bit of plastic. The main two terminals do NOT connect to the chassis at all - they just carry the current between the MAIN and AUX by means of the relay connection (when made).
The VSR does NOT provide voltage increase as a DC to DC charger does, and is not a substitute for one either. It is for those of us who would rather rely on an automatic connect/disconnect than an unreliable memory!!!
@Middo , if you have a Ford Everest, it is likely that your vehicle will have a "Variable Voltage Alternator" according to the RedArc listing above. With voltages varying between 12.3 and 15.0 volts, this would play havoc with a VSR, even with the 8 sec delay preventing the relay from disconnecting during a momentary drop in voltage. Hence the problem in providing a useful voltage for fridges and other electrics. Thus the absolute need for a DC to DC charger to maintain a workable voltage with those sort of alternators.

 

[Middo]

Have to say that I have not noticed any problems. When the van is hooked up and car running, we check the fridge to make sure the 12 volt light is on then off we go. Heading off on Monday to Canberra. Just not sure which way yet, depending upon road conditions.

 

[Boots in Action]

Have to say that I have not noticed any problems. When the van is hooked up and car running, we check the fridge to make sure the 12 volt light is on then off we go. Heading off on Monday to Canberra. Just not sure which way yet, depending upon road conditions.

@Middo , you probably won't see any problems on idle. Note what RedArc says: "These alternators vary output depending on driving conditions at the time". You would need to have a visible volt meter across the fridge terminals whilst driving to pick this up. Safe travels.

 

[Drover]

Way to go @Middo , my memory hasn't gone to mush quite yet it seems.... youv'e a good set up i reckon.
In these days of electric everything on vehicles I think I would prefer a Fridge Switch, which is basically a movement switch so shuts off power when stopped and being usually located at the fridge means you can hook up another vehicle.................... With your set up the the ECU/BCM will see a certain load being drawn and keep the alternator loaded up as they use more than battery voltage sensing for regulation.... It used to be that you could get Ford to shut down the smart alternator bit, not sure if still possible though but could be possible with quality scan tool .

Heading off on Monday to Canberra. Just not sure which way yet, depending upon road conditions.

We roll on Sunday, we are going down the middle so we don't wander through any ACT Declared spots in NSW and won't need to get a permit, Newell Hwy is out at the moment due to Moree and Coona being in the zone and Byron being an area of concern or something but we stay away from the coast anyway..... Roads all look okay.................

 

[Middo]

Yep we might take the New England highway. Stop at tamworth

 

[Drover]

Manilla Sunday and Monday night we hope to parked up at Molong Showground but could be Canowindra or Cowra....chance of deviating to a creek or Dam is possible.

 

[jazzeddie1234]

Slightly different thought - my 3185 12v flashing was caused by a bad connection at the fridge circuit board. The spade connectors are running beyond their design limit (at 16 ish amps) and mine overheated.

I have heard a quick test is to drive with headlights on because it turns the smart voltage feature off?