Dometic NDA1402 Side by Side issues solved

[e4services]

I thought I would write a post after spending days, hours, hands on with the unit and reading online of everyone else problems.
Basically the unit I was working on the freezer just would not get cold enough.
Did some reading.
First thought was the Thermistor. By pulling the connector off the control board you can measure the resistance of each of the 4, pins 1-2 and 3-4 (You have to remove them from the board to measure. leaving them connected to the board adds the boards circuits to the reading). I measured them warm and cold, they all should be pretty close to each other 1.9k ohms warm. Cold is a bit tricky for the two in each compartment measure different temps. One the air, the other the cooling fin/plate. The frig 4.7k/7.1k. The freezer 12.9k/20.5k. Yes the resistance goes up as temp goes down. So all the thermistors were good.
Kept reading. Fan in the freezer? looked into where it was and sure enough this fan was not running.
Figure it had failed, did some more searching, found the service manual and parts diagram to try get the fan out. FYI these fans are a standard cooling fan, described as "75mm x 30mm 7530 12V Dual Ball Bearing DC Brushless Cooling Blower Fan AV-F7530MB" $4 on Amazon. The $70 Dometic replacement come with the wire length and connectors to suit, but for $65 you can just splice the new one in.
With the freezer fan in hand, tested it. By golly it works. So I put it back in and chased down the control board, or "Power Board" as Dometic refers to it, was not turning it on. FYI, turning it on for this control is by giving it a ground, 12V+ is always there. Don't ask. I jumped the ground from the heater wires that are in the freezer to the fan and wala, fan runs and after a day the freezer was at 7 degrees.
NOW, why was it not on. Did some more reading. Owners reporting by using the Test Mode, holding down the SET button while turn the frig on, the fan would turn on, others reported the Door Switch test would always show the Freezer door open. Another owner report that the fan turns off with the door open (the frig doesn't work that way, fan always on).
So is it the switch? Dometic, I read, told others to replace it. SO I checked it, the switch disconnects when closed. Worked fine, but the board still shows the door open. The guy at help@snip-the-tip.com who makes a replacement thermistor FYI, suggested there maybe some resistance being place in the switch wires.

Well, by gosh, I find on the wiring diagram, they splice into the wires and run both of the switch wires up to the Ice Maker control board. From what I can figure, they defeat the ice maker from working when the door is open.
Pulling the 4 pin connector from the Ice Maker Board, the Freezer Fan starts running and the Test shows the door closed now.

Is it that $100 Ice Maker Board is bad, defective, a bad match to the Power Board. Who know, I am going to just leave it disconnected for now and put everything back together

[Old-Biscuit]

Did you check the wiring connections in the 'interconnection box' on rear wall of freezer?


Defrosting heater, defrosting element in water drain line and freezer fan wiring.
Fan ---red to red/black to black

[e4services]

Not sure what your input adds at all. I did say I dismantled the interior, did I not? And that I found the problem?
FYI The freeze fan has a connector in the box you speak of, only one way to put it back together. Your reference seems to be that of the frig, which has a bear wire end connector for the fan.

[e4services]

UPDATE: So as I said the problem arose from the connection from the Power Board for the frig to the Ice Maker Control board. Removing this connection allowed the Freezer Fan to run as it should.

BUT upon reassembling, I found that the through door control panel for the ice/water dispensing requires this 12VDC that it appears is supplied by this connection.

SO, digging deeper, there are three wires spliced from the Frig Control. Yellow, white and Black. THe wiring diagram depicts this in the top left corner, the yellow and white from the freezer switch and the black from the freezer light.
The Black is the ground wire for the light.
The White is a 12VDC line that runs to the switch
The Yellow is the return from the switch. The switch closes when the door is open and 12VDC comes back to the "Power Board". What was happening is a small leak was coming back the Yellow wire from the Ice Maker board.
Not sure why the connected this Yellow wire to the Ice Maker, so I cut the sliced wire from the Ice Maker board.

Everything works as it should now, Fan, Unit's internal temps are 36 and 1 degree, Ice Marker as well as the through door controls. So there you go, hope it helps somebody.

[avfordguy]

Kinda same issue on dometic 2007 in a class c would not cool @85 degrees outside temp, checked fan (fridge in in a slide) no fan, checked fan fuse blown, replace fan fuse blows again, checked snap switch h on condenser and when snap switch closes to turn on the fan at 165f it was shorted to ground, replaced snap switch with a lower temp one (145f) from Ebay and added a second fan, best RV fridge in 105f direct sun in so texas, 2 fans running, holds -5 in freezer and 36 in fridge and it cycles off and on, if your in a hot climate 95+f add a second fan!!

[TexasTom]

Originally Posted by e4services

UPDATE: So as I said the problem arose from the connection from the Power Board for the frig to the Ice Maker Control board. Removing this connection allowed the Freezer Fan to run as it should.

BUT upon reassembling, I found that the through door control panel for the ice/water dispensing requires this 12VDC that it appears is supplied by this connection.

SO, digging deeper, there are three wires spliced from the Frig Control. Yellow, white and Black. THe wiring diagram depicts this in the top left corner, the yellow and white from the freezer switch and the black from the freezer light.
The Black is the ground wire for the light.
The White is a 12VDC line that runs to the switch
The Yellow is the return from the switch. The switch closes when the door is open and 12VDC comes back to the "Power Board". What was happening is a small leak was coming back the Yellow wire from the Ice Maker board.
Not sure why the connected this Yellow wire to the Ice Maker, so I cut the sliced wire from the Ice Maker board.

Everything works as it should now, Fan, Unit's internal temps are 36 and 1 degree, Ice Marker as well as the through door controls. So there you go, hope it helps somebody.

So I followed your path, and so far so good, fan comes on, defrost now works! But the interior light no longer worked, so I put a diode in the yellow wires to prevent the voltage "leak" back to the main circuit board. I have restarted the fridge and am hoping the ice maker starts working again.

Thanks for the info!

[TexasTom]

Nope, ice maker no longer works. Now have to track down if it is a coincidence or a different issue.

[Tractormike]

Originally Posted by e4services

UPDATE: So as I said the problem arose from the connection from the Power Board for the frig to the Ice Maker Control board. Removing this connection allowed the Freezer Fan to run as it should.

BUT upon reassembling, I found that the through door control panel for the ice/water dispensing requires this 12VDC that it appears is supplied by this connection.

SO, digging deeper, there are three wires spliced from the Frig Control. Yellow, white and Black. THe wiring diagram depicts this in the top left corner, the yellow and white from the freezer switch and the black from the freezer light.
The Black is the ground wire for the light.
The White is a 12VDC line that runs to the switch
The Yellow is the return from the switch. The switch closes when the door is open and 12VDC comes back to the "Power Board". What was happening is a small leak was coming back the Yellow wire from the Ice Maker board.
Not sure why the connected this Yellow wire to the Ice Maker, so I cut the sliced wire from the Ice Maker board.

Everything works as it should now, Fan, Unit's internal temps are 36 and 1 degree, Ice Marker as well as the through door controls. So there you go, hope it helps somebody.

That fixed the same problem I had to a tee! Just wondering I even went so far are installing new transistor of the ice maker board but that didn’t help. Do you think it could be as simple as the diode on the ice maker board? I have spent days troubleshooting this just like you and happened to run across your post today right before I was going to rio this thing out the window and install a residential in its place.