Left over fridge parts?

[PP]

I had to replace the circuit board on my Dometic this week and I couldn't wait for a Dinosaour to ship since the nearest RV dealer had a Canadian one in stock for the same price. However, they have redesigned the boards since 1995 and I had to do a little rewiring. Hence, I had some pieces left over, the main one being a black plastic box @1.5" Wide X 1" thick X 3" long that the eyebrow plugged into and then into the board. I left it off when I installed the new board since I couldn't find any reference to it on the schematic and simply plugged the eyebrow into the plug on the new board. It seems to be working fine, but what was that part that I left off? I had to reconfigure the entire harness on the board according to the schematic because all the jacks were in different order among other things; turned out to be quite a project considering I thought since I was going with a 'Genuine Replacement Part' it would be as simple as 'Plug-and-Play' LOL.
Thanks, Will