12 fridge power supply

PS The instruction mentions that you might have to use a load resistor on the 5 volt rail. I didnt do this and it still works fine.

We have used these for running cameras. Not ideal as they are switchmode and have some high end interference (very minute). But for the fridge will work well. The only problem is they are not exactly small. ie you can't fit them in the compartment the factory ones slip into to take with you.

For round the house though, would be perfect. Should be able to buy cheap ones from any computer store for about $40 brand new.

Agreed, they work well.
I am currently using a 200 watt one, albeit modified. In its original form, the overall voltage regulation is on the +5v rail, leaving the +12v unregulated. I have modified it so that the regulation is now on the +12v rail (and cranked it up a bit). Also swapped the 5v shottky diodes with the 12v diodes (5v diodes are bigger) to give higher current out at 12v. I can get about 14A out of mine now.
Some power supplies do like a small load (say 0.5A) on the +5v rail, but mine works fine without a load.
Also, it is not recommended that you put one of these across a battery; an earlier one of mine died a serious death, tho I've modded the current one to work ok - too much to describe here.
Another suggestion is to connect the fan via a thermal switch (avail from Jaycar), so the fan cuts in when the heatsink gets to about 60deg. This means it rarely cuts in, and therefore little noise.
And remember that there are some serious AC and DC high voltages present, where quite often the construction of the power supply doesn't do much to separate the high voltage from the low voltage, so when modiying it, try not to disturb anything which could later affect the high voltage side.
Cheeers, Gerry