The eyebrow lights and controls of the second generation Dometic refrigerators are actually a part
of the eyebrow circuit board, which gets its 12 volt power from the main board
at the bottom rear of the refrigerator. A micro processor on the eyebrow board communicates with a micro
processor on the main board, translating user input into settings for the main board. For example, if
Auto were selected, it would "tell" the main board to be in a mode where AC (120 volt) is to be used
as a heat source if available and where gas is to be used if AC is not available. The main board takes
control from that point on, until the user makes a change at the eyebrow. On models that have a
temperature control on the eyebrow, the eyebrow sends a temperature setting to the lower board.
On models without the temperature selector, there is also no micro processor. On those models,
the eyebrow board turns the main board on and determines Auto or Gas by means of its switches.
The main board then operates in the middle temperature setting, unless over ridden by the user
pushing the manual button.
The table below can be used to test the input and output of the cable connection at the board. This table, in conjunction with a similar table on the main board page, will help you in isolating a problem between the eyebrow board, main board, and the cable connecting the two boards. There is no test for the brown wire (communication link). In general, if the appropriate lights are lighting up on the eyeb row, the eyebrow would be good and any problem would lie elsewhere.
Second generation models with an Auto/Gas button and a temperature control on the eyebrow also have a
diagnostic sequence available through the eyebrow. When activated, the refrigerator can be cycled
through a test of the components. This sequencing can be done either automatically or manually.
For auto sequencing, depress the Auto/Gas button to the Auto position. Each of the temperature lights will light in order for 4 seconds, each indicating a test of a different component or system. The table below will show what light corresponds to what test. The eyebrow doesn't actually test the component, but causes the main circuit board to put voltage to the various components for testing.
For manual testing, place the Auto/Gas button in the Gas position. Use the Temperature Selector button to cycle through the various tests. You should turn the manual gas valve off at the back of the refrigerator when testing the gas solenoid for more than a few seconds. When voltage is present at the solenoid, the valve is open and gas would be passing through it, if it were able to. This, of course, would be a dangerous situation.
A failure of the main board during any of these tests would indicate a problem with the main board. However, be sure to check the appropriate fuses before condemning the board.
RV Mobile Inc. 11715 HWY 99, Everett, WA 98204
The owner of RV Mobile Inc. apparently suffered a heart attack and the original website was shut down.
It has been reposted here to preserve this wealth of information RV refridgerator information.