Anyone that uses an RV in the hot part of the summer knows that these combination refrigerators do not cool very well when it is hot outside. It is really just a problem with air flow. Open up your compartment at the rear of your refrigerator and just feel the coils during the hot part of the day. They are so hot they will just about burn you.
I solved the cooling problem on our Tradewinds motor home with a couple of 4.8 inch server cooling fans I picked up on eBay for $10 each, including shipping. I mounted them in the refrigerator roof vent, exhausting upward. Here they are mounted in a couple of brackets I riveted up for them:
Here they are mounted in the roof vent. This is standing on the roof looking straight down with the cover removed from the vent:
These fans only use about .6 amps each at 12V. I took power off the supply block for the refrigerator and put a 2 amp fuse inline. For the sake of convenience, I mounted a switch on the front control panel and just use these fans when it is above 80 degrees outside.
I am really happy with them and so is our refrigerator. We are sitting here in Austin, TX at 100 degrees in the shade and our refrigerator thinks it is in Canada. Easily holds a steady 39 degrees in refrigerator compartment.