My Engel has 2 seperate plugs. 1 for 12 volt and the other for 110v. I don't think connecting 12 volt to the 110v plug is a good idea.
If you burned something up then you have a really expensive paper wieght.
I would just run a fused wire to the 12 volt side of the fridge and find a connector that will work, I know Radio Shack has all kinds of oddball electrical fittings that may work for you.
Good luck.
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Jess
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