Looking for circuit board from older ARB fridge/freezer

danielj_co

Rock Stacker
Joined
Jul 1, 2021
Messages
4
Hey, folks. I have an older (circa-2010) 47L ARB fridge/freezer. I've had it in all my vehicles over the years, and it has always been amazing - super reliable, low power draw, efficient. I just got back from a couple of weeks on the road in my 3rd gen 4runner (which isn't at all relevant to the problem at hand, but this *is* a Toyota forum) and fairly early in the trip, the fridge stopped working correctly on DC. I've checked all the things - I'm getting a steady 12.6 volts all the way to the danfoss module, and I just replaced the battery with a new AGM. ARB thinks that the problem could be the danfoss control unit or the circuit board, but they don't have that old model anymore. And it's not in the budget to shell out for a new one.

So - my question is - do you have an old ARB fridge that crapped out in some other way, that I could buy for the control modules and circuit boards? This fridge is like family to me, and I don't want to lose it. It still works great on AC, but that doesn't get me into the woods.

Thanks,

Daniel
 

DaveInDenver

Rising Sun Ham Guru
Joined
Jun 8, 2006
Messages
11,437
Location
Mesa County
I assume ARB walked through the obvious stuff like the 12V fuse, cable, etc? Did they ask you to verify that the interior light turns on or if there's any fault lights or a code displayed?

Does it make any difference if the truck is running or not? IOW is it possibly voltage related, works at maybe greater than 13.8V but fails below some threshold.

If nothing is working on 12V but things do work on 120VAC it might not be the controller. If the fridge appears to be on (e.g. interior light and display come on) but isn't cooling then it's probably the controller.

That's actually good because the controller is part of the compressor and Danfoss maybe could fix you up. IIRC the Danfoss part number for your compressor is BD35F and what you're after is the Danfoss part number 101N0500, which is the controller. Whether that's still available or not I don't know, though.

 
Last edited:

danielj_co

Rock Stacker
Joined
Jul 1, 2021
Messages
4
Thanks for the detailed reply!

D'oh! I left out the error code. It blinks once every 5 seconds, which means it thinks the available current has fallen below a range from 10-11.4 volts depending on the setting, and it stops cooling at that point so it doesn't kill the battery. This is why I was checking to be sure I was getting adequate voltage to the fridge. And I'm getting 12.6v out of the wires where they go into the danfoss.

I have spoken with ARB. David in Seattle suggested checking the voltage to the danfoss and running the test in the service manual to test the compressor module, which passed when I ran it (removing the connectors from C and T on the danfoss and jumping them with a wire, and the compressor should start, which worked).

And it works fine on AC, including through an inverter on a different outlet (the DC cable is wired directly to the battery, with a 15A fuse inline).
 

DaveInDenver

Rising Sun Ham Guru
Joined
Jun 8, 2006
Messages
11,437
Location
Mesa County
Jumping C to T is bypassing the thermistor, which if it runs should have eliminated the controller as the issue.

it sounds like you're hitting the low voltage cut off.
 

danielj_co

Rock Stacker
Joined
Jul 1, 2021
Messages
4
But I'm getting 12.6 volts at the entrance to the danfoss, and the low voltage cutoff is set to 10.1v (low). Something seems to be reading the available voltage incorrectly.
 

DaveInDenver

Rising Sun Ham Guru
Joined
Jun 8, 2006
Messages
11,437
Location
Mesa County
But I'm getting 12.6 volts at the entrance to the danfoss, and the low voltage cutoff is set to 10.1v (low). Something seems to be reading the available voltage incorrectly.
Are you watching it when the compressor is trying to start and running? Low voltage doesn't necessarily mean it's always low, it could be a transient. If it's something like this you probably won't even see it with a multimeter unless it's fast and set to record min and max.
 
Last edited:

danielj_co

Rock Stacker
Joined
Jul 1, 2021
Messages
4
Measuring the voltage at the entrance to the danfoss when the compressor kicks on? I have not. I'll try that tomorrow - getting some rain! What would a voltage drop when the compressor runs tell me?
 

DaveInDenver

Rising Sun Ham Guru
Joined
Jun 8, 2006
Messages
11,437
Location
Mesa County
Measuring the voltage at the entrance to the danfoss when the compressor kicks on? I have not. I'll try that tomorrow - getting some rain! What would a voltage drop when the compressor runs tell me?
If the voltage dips to 10.4V or lower (I think) the Danfoss controller will kick out. It's going to be short though, like I say a fast meter recording or an oscilloscope will be required to see it.

If you have not tried you could try a power supply or battery connected to the fridge with fairly large (say 12 or 10 AWG or larger if you can) cables that are very short. Also make sure all the 12V connections are clean, have no corrosion or breaks.
 

nakman

Club Secretary
Staff member
Moderator
Joined
Aug 23, 2005
Messages
13,008
Location
north side
The voltage may only be half of the story here... it's possible you have really low amperage, caused by a bad cord connection, or the little fuse inside the plug itself. I wouldn't go any further until you can rule out the cord completely.

With your multi meter test to see which terminal on the plug/fridge is + and which is -, then label your fridge. Then you can put wires with terminals directly to it to see if the problem persists.. if you expand the wire terminal just a tiny bit with a screwdriver it will slide onto the prong nicely and stay put really well. Get the power from a fuse block, or directly to a battery, just make sure you have an inline fuse on the + side, as you'll probably touch them at least once. the second time you do this you'll think to put the fuse in after you hook the wires up.

That's how 2 of my fridges are wired all the time, the wires go from a fuse block directly to the fridge, I ditched the cords years ago for improved performance, including reducing the low voltage error I was getting. This is what it looks like on a Dometic.
IMG_4460.jpg



If you can bypass that cord completely and it solves your problem, then you could add this to the other ARB cord thread https://risingsun4x4club.org/xf/threads/different-connection-for-arb-fridge.31245/ and if not then you know it's not the cord.
 
Top