Dometic RM3663 problem

Success! After a couple of hours the fridge was cooled down to the proper temperature. I believe that it was the lower circuit board that was bad. My fridge is in a 1998 model truck camper so it has a few years on it.

Finally made some progress on this project. I replaced the eyebrow circuit board and nothing worked. I replaced the lower circuit board and finally have working lights on the eyebrow. Have it plugged in now waiting to see if it cools. The heating element is hot so I'm guessing that it just takes some time for things to start cooling down.

Easy items first. Ignore 120 volt items at this time. Refer needs 12vdc to operate controls, eyebrow also. Is 12vdc arriving to refer input terminal connector. If not go to rv fuse panel within coach. If yes, go to both sides thermal sensor fastened to boiler area of refer about 7" above flame area. If yes go to fuse under lower circuit board cover. If not press reset button on thermal switch attached to chimney. All these items are at rear of refer accessed thru lower exterior service vent.

Moved fro the TC Forum for more input.

Wayne
Moderator

I suppose youve come across Service tips, at BryantRV
http://bryantrv.com/docs2/docs/servtips.pdf.
It also identifies (p.25) the eyebrow wires color location/pins on main & upper board (but not function as you noted-) between the 2 which/wher to test.... Curious where you found that? It mentions the PAL-but sure sounds like outlined tests are with meter? Few simple tests on main/uppper and cable.
Not knowing I assume that main board feeds the eyebrow power which in turn tells main board what to do? Curious it mentions a failure mode if eyebrow fails and should continue to run, never noted that.
Not much help but more info if you hadnt already found.

Broken wire would not be my first thought. I would think it would be a bad board before that.

I found some info on the pin that goes up to the eyebrow board.

Pin Number.....Wire Color..........Reading
1....................Green................12 volt +, when eyebrow switch on
2....................Open.................Open
3....................Black................12 volt +, when eyebrow switch on
4....................Orange or White..12 volt +
5....................Red..................12 volt -
6....................Brown................Communication link

My connector has six pins but only 5 wires. I will check the voltage of the wires going up to the eyebrow unit. Then I can check the wires at the eyebrow unit to see if there might be a break somewhere. Next step after that would be to pull the fridge and see if I can see any breaks in the wire.

Toddupton wrote:
Is the top board plugged in all the way to the connector?

Yes, checked that.

Is the top board plugged in all the way to the connector?

Toddupton wrote:
Did you check all of the small glass fuses on the board?

Yes, checked them all for continuity and then replaced them all with new ones.