What you have is a Dometic RM 66 (also known as RM 660) refrigeration unit, this is who made the refrigeration unit, when you go for any parts this is the number you will use for the chassis when the hadco number comes up unknown, the box itself is a hadco unit, their number will get you parts located for this box, its guts is another story...Next when you are referring to the electric mode of operation is this 12v or 120 volt? Your model suggests its 120 volt.
Please note when operating in electric mode the box is slower to cool and must be level side to side, and front to back...older refrigerators are not very forgiving on this point.
Also this may have a gas control knob which excludes 120 volt operation via a built in switch if the gas knob is selecting gas and is turned on it locks out the electric...(even turned a wee bit) Does it run on gas at all when you light
I am asking the questions as part of a procedure I need to use to help you...It helps me set the stage to establish what is going on there in my mind and understand the mode of operation you are in regarding your refrigerator
..."bear with me my questions are not to make you think its complicated, these boxes are made in many variations and in the early days there was no standardization of operation"
...Next on some models the gas/elec knob had a sliding plastic plate between the knobs, does yours? Can you send a pic.
The RM 66 did on some configurations have a sneaky toggle switch located in the back of the refrigerator
...It was operated from the front by the mode selection knob (Gas/Elec knob) the knob was mechanically connected by a rod which was notorious for disconnecting itself (a fashioned pin)...when this happens the select mode knob goes loose, feeling wobbly. A few more questions and I may be able to suggest some action.
If its 120v you betcha there will be a plug or switch somewhere...Here is something to remember the way this box is installed can be very different trailer to trailer so be curious, crawl all over it, and be very observant...the changes prior owners can make to the trailer alone can be elusive and turn you into a Sherlock Holmes.
There is a parts blow up and service data in the document center on this site under the dometic name (RM-660)...I am still getting used to the idea the document center is avilable.
I will wait for a reply...
The fridge is a HADCO HR-6 in a 1976 Timberline. The power is on, and gets to the fridge. Is there a switch besides the knobs in the front that I need to know about? The stove had a switch under the burners I had to turn to use the burners, and it took me some time to find it. I bought it 8 months ago from a dealer who apparently didn't know squat about it. Is there a fuse or fuse box I need to know about? Thanks and God bless.