Dometic RM2454 refrigerator, no lights on display (eyebrow)

[Tershe]

I have recently purchased a 2013 Casita. Unit has a Dometic RM2454 refrigerator (3way). The display (upper circuit board) has no lights. Wondering if anyone has any suggestions or ideas as to this problem? Here’s what I’m aware of and have checked:
1) The display requires 12volt power from the lower circuit board, which it’s not receiving.
2) The P1 in the lower circuit board is not outputting the 12volts on the harness, orange and red wires leading to the above display. (meter checked).
3) The lower circuit board is receiving AC 121 volts at the board. Also receiving DC 12.6 volts at the board (metered).
4) The 3amp fuse is passing the DC 12.6 volts and the 5amp fuse is passing the AC 121 volts.
5) There is a 30amp in line spade fuse from the 12volt terminal block and it’s ok, meter checked.
This is the extent of what I know, or think I know. I’m aware that some units also have a thermofuse that may be interrupting the 12volts and can be reset, but I see no such fuse on my unit.
I apologize for the length of this post. Any ideas or suggestions would be appreciated.

[BFL13]

Tershe wrote:
The pos probe is on the orange wire out of P1, which is 12 volt+. The neg probe is on the red wire out of P1, which is 12volt-.

I have just replaced the lower circuit board, with the same outcome, no DC output at P1. What else may interrupt the 12 volt input at the board from the output at P1?

The diagram on page 11 in the link above seems to show that C has :
green to P1-1,
orange to P1-4
red to P1-5
brown to P1-6, and
black to P1-3

I don't have which is 12v plus or minus. I would suspect green to be neg but ? I would try the meter on various combos to see if there is 12v on any combo.

I would try the pins in the connector and not the wires on the plug.

I would try to supply 12v to the C plug directly once you are sure of the right pos and neg wires from another source to see if it lights up at all.

EDIT--or just do what Old-Biscuit says--yay, we are saved! 🙂

[Old-Biscuit]

See Pg. 13 ---5.8 section Testing Upper Circuit Board (Display)

Follow the test procedures to ID Issue

Upper Display Circuit Board
OR
Harness to Upper Display

[Tershe]

The pos probe is on the orange wire out of P1, which is 12 volt+. The neg probe is on the red wire out of P1, which is 12volt-.

I have just replaced the lower circuit board, with the same outcome, no DC output at P1. What else may interrupt the 12 volt input at the board from the output at P1?

[BFL13]

We need help!

Anyway, where are you putting the meter neg prob when the pos is on P1?

I would try the pos probe on P1 and a different ground for the neg to see if it just needs a ground, and vv, I would check the ground you are using with P1 and some other place that has 12v for sure as pos and see if you still get 12v so P1's ground is live. Then you know if P1 or its ground is guilty.

No idea what to do about it though 😞

[Tershe]

That’s correct, no output volts at P1 on the board.

[BFL13]

http://techsupport.pdxrvwholesale.com/wp-content/uploads/2017/09/Dometic-Refer-Model-RM2454-Wiring-D...

So you unplugged the eyebrow and there is no power at P1 where the eyebrow plugs in?

[Tershe]

Thanks for the reply. Yes, the interior light comes on when the door is opened.
The 12 volt output was checked on the plug on the lower circuit board, not the eyebrow harness. Sorry, I should have indicated that.

[BFL13]

Does the inside light come on when you open the door

The plug for the eyebrow that goes in where the circuit board is --pull that and replace to see if was a bad connection