Suggestions for wiring up Dometic

[kentoe]

I just picked up a Dometic fridge over the weekend off Craigslist (CFX35-US) and I'm stoked. I was looking for some advice on re-wiring one of the 12v plugs.

I set the battery voltage detector to high since I'm just using the stock battery currently but noticed that when I shut off the Jeep it doesn't really stay on like it should on the non ACC cigarette lighter. I'd expect atleast a few hours if not a day from what I've read. However, I noticed after lots of googling that it makes sense that it's not able to accurately measure the voltage from those plugs and the thin OEM wires.

I wanted to cut the 12V plug in half and wire up some Anderson powerpole connectors to it and the other half so I could re-use the cigarette lighter function if need be. However, I wasn't sure what to use to wire the fridge directly.

If I was going to run a direct power to the fridge for the rear from the battery, would it be fine to use 14 gauge wire with a 7amp inline fuse? Or should I go with something like 10 gauge? I was contemplating putting a blue sea fuse box in the back if I ran 10 gauge, but I use the soft top and can't really find a good place to put something like that instead.

Any advice is appreciated! Worse comes to worse, I may have to pickup a power pack from amazon in the meantime and just in case since I'm only using one battery.

 

[Corey]

I am running 8 gauge stereo power amp wire from the aux battery up front to the rear to power my National Luna fridge.
Both wires straight to the battery with a heavy duty ANL fuse.
Fridges like their power directly to the battery, and the ground wire also to the battery, and not to the frame.

 

[kentoe]

You might as well run 10awg. Paired landscape cable is great for this sort of thing. On 10awg, Fit a 20-30 amp OCPD.

I noticed in another thread you suggested landscape cable, but I looked at home depot / lowes and I couldn't find 10awg at a reasonable price if at all.

Also, OCPD? Forgive me for my ignorance, just sort of getting into the world of 12v as of the past month or so.

I am running 8 gauge stereo power amp wire from the aux battery up front to the rear to power my National Luna fridge.
Both wires straight to the battery with a heavy duty ANL fuse.
Fridges like their power directly to the battery, and the ground wire also instead of to the frame.

Wow 8 gauge to the fridge itself? Is the standard cable that comes off the fridge that I'd be splicing off of even that large of a gauge? Would that defeat the purpose of running a larger gauge wire to a lower gauge OEM plug?

Regardless, yeah I was thinking of doing the power directly to the battery as well as the ground wire.

Thanks

 

[vartz04]

you can get 10 gauge speaker wire pretty cheap. basically the same stuff ($15 or so for 50' of paired (red/black) wires on amazon) https://www.amazon.com/dp/B00J35SW9Y/ref=cm_sw_r_cp_dp_T1_5e0Fzb79SQWAY

anderson now has a panel mount power pole set up with 2 outputs. its $20 but totally worth it. I used one in my solar set up.

https://powerwerx.com/panelpole-panel-mount-powerpole-housing

would make for a pretty clean install. I am considering doing the same thing once I get my own vehicle (company vehicle is going away soon i think)

 

[Corey]

Wow 8 gauge to the fridge itself? Is the standard cable that comes off the fridge that I'd be splicing off of even that large of a gauge? Would that defeat the purpose of running a larger gauge wire to a lower gauge OEM plug?

Regardless, yeah I was thinking of doing the power directly to the battery as well as the ground wire.

Thanks

Oooops, I had a typo above, no ground wire for power to the fridge should go to the frame.
Both wires should go directly to the battery.

The gauge I am running is what tech support at National Luna told me to run for the length from up front to the back.
When a fridge compressor first fires up, it takes more juice to turn it over, and the heavier gauge helps.

The reason the gauge has to be bigger than the plug wire itself is the power wire is going a greater distance than the short cable supplied with the fridge.

 

[kentoe]

you can get 10 gauge speaker wire pretty cheap. basically the same stuff ($15 or so for 50' of paired (red/black) wires on amazon) https://www.amazon.com/dp/B00J35SW9Y/ref=cm_sw_r_cp_dp_T1_5e0Fzb79SQWAY

anderson now has a panel mount power pole set up with 2 outputs. its $20 but totally worth it. I used one in my solar set up.
https://powerwerx.com/panelpole-panel-mount-powerpole-housing

would make for a pretty clean install. I am considering doing the same thing once I get my own vehicle (company vehicle is going away soon i think)

Thanks, I think I'll probably make a permanent install for the time being for my 12v wire. It looks like the 10 gauge anderson connector is more of a U shape that you form to the cable. Probably tough with a regular crimper tool to crimp. Looking like a proper anderson crimper will be required.... will go this route down the road considering the damn crimper is $30 alone. It'll most likely be used solely in my Jeep anyway as well as in the house.

Oooops, I had a typo above, no ground wire for power to the fridge should go to the frame.
Both wires should go directly to the battery.

The gauge I am running is what tech support at National Luna told me to run for the length from up front to the back.
When a fridge compressor first fires up, it takes more juice to turn it over, and the heavier gauge helps.

The reason the gauge has to be bigger than the plug wire itself is the power wire is going a greater distance than the short cable supplied with the fridge.

I think we're on the same page here, yes am planning to run both POS and NEG wire from the fridge 12v wire to the battery.

Ah okay, makes sense then. I looked up the max amp for this dometic 35 and it seems like 12v will be 7 amps so I think 10 gauge will be good/safe for the given length I'll be using with an inline fuse.

 

[v_man]

I have a Dometic 50 qt. The compressor does not run continuously. The fridge can be considered 'on' without the compressor running.

FWIW I have my voltage detection settings on medium and I've left the fridge plugged in for 24 hours with no impact on my ability to start the truck.

The fridge is wired on a 10 foot run of 12 gauge and that gauge keeps the Dometic happy. Avoid the urge to overwire the fridge, 12 gauge should be fine...

 

[kentoe]

I have a Dometic 50 qt. The compressor does not run continuously. The fridge can be considered 'on' without the compressor running.

FWIW I have my voltage detection settings on medium and I've left the fridge plugged in for 24 hours with no impact on my ability to start the truck.

The fridge is wired on a 10 foot run of 12 gauge and that gauge keeps the Dometic happy. Avoid the urge to overwire the fridge, 12 gauge should be fine...

Thanks for your input. Good to hear about your experience with the voltage detection, hoping to have that flexibility especially for an upcoming Acadia trip.

Nice to hear that your 12awg has been working great. I already ordered all my wiring for 10awg though and should be here tomorrow! Unsure how far the length will end up being, I would think at max 20 feet so I wanted to be safe.

 

[LandCruiserPhil]

ARB makes a nice fridge wiring kit and they use #10. Using ARB research and design I also used #10 for my set up.

 

[Russ Chung]

I have a Dometic 50 qt. The compressor does not run continuously. The fridge can be considered 'on' without the compressor running.

FWIW I have my voltage detection settings on medium and I've left the fridge plugged in for 24 hours with no impact on my ability to start the truck.

The fridge is wired on a 10 foot run of 12 gauge and that gauge keeps the Dometic happy. Avoid the urge to overwire the fridge, 12 gauge should be fine...

I respectfully disagree. The reason for using 10 gauge wire is not because of the load, it is to reduce the voltage drop between the battery and the fridge when the engine is not running. As kentoe said in the first post, the fridge runs fine on the non ACC cigarette lighter plug (which I believe is 18 gauge) when the engine is running, but the fridge won't run from the battery with the low voltage shutoff set on high. My fridge is about 10 feet from my battery. With 10 gauge wire and a fully charged battery and a medium setting on the low voltage shutoff, I can go two days in moderate temperatures or one day in summer temperatures without triggering the low voltage shutoff.

Also, even though 10 gauge wire is capable of handling 30 amps, I use a 10 amp fuse because that's all the fridge needs.

 

[Chris Boyd]

2nd this comment. Voltage sense and line drop is a key with these fridges.

Also you'll find some other reasons to have aux power back there, so why not pull something bigger up front for the effort?

 

[Corey]

I have to third the comment as well.
In my research to get power to my new fridge, the bigger wire is needed to prevent voltage drop over a distance, and to keep a thinner gauge from getting warm/hot.

The thinner wire I had in the rear for the two 12v outlets (one was used for the old school ARB fridge) was around 16 gauge I think, and while sufficient for the ARB fridge, only the LED panel would light up on my new fridge, even with the rig running the Luna would not fire up on that thinner gauge.

 

[kentoe]

Good to hear the consensus on going with something like a 10 gauge wire for the fridge and people's experiences. Agreed about running something more beefier (like 8 gauge) for more accessories in the future back there to something like a blue sea panel.

I'm not sure where I'd put it at the moment so it looks like I'll be going with Battery -> 10 gauge inline fuse (7.5 amp or 10 amp) -> 10 gauge wire -> cut off cigarette wire for fridge. And will be putting anderson's in between sometime in the future. With of course the negative wire going all the way to the battery too.

I have a source panel under the hood, so most of the future additions will be run to that source panel for the things I have in mind at the moment (lights, water pump, compressor)

 

[furbucket]

Bigger gauge is better...

Manual states that fridge is a 7amp load, turn on voltage could possibly be higher so a 10amp fuse would be my choice (also, the plug it came with utilizes a 10A fuse already...)

When using the battery monitor feature in HIGH the fridge will cutoff at 11.8 volts and not restart until it sees 12.6 volts. Using some free online calculators and assuming a length of 10', voltage drop for:
18awg is roughly 7%
14awg is roughly 3%
10awg is roughly 1%
Depending on your battery voltage you can do the math and see how easy it is to reach the cutoff threshold- and that's only at 10' distance... those percentages only get higher with longer runs and more load.


Sent from an evil pocket calculator with a flashy screen

 

[LandCruiserPhil]

There is a good reason ARB uses #10 in the fridge wiring kit they sell.