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The RVer's Open Forum / GENERAL RV DISCUSSIONS / Fan in Norcold Fridge

Steve D Moderator User ID: 1418774	Feb 28th 2:47 PM I have used 12 volt computer fans inside the box of my RV refrigerators before and it really helped make the cooling more even throughout the box. Normally, I have wired the fan ACROSS (that’s correct, across) the door switch. For those that are not familiar with this wiring, the reason it works is that the current drawn by the fan is MUCH less than the current required to light the lamp. Therefore, with the fan across the switch, when the door is closed, the fan is effectively in series with the lamp and runs. When the door opens, the switch shorts out the fan, connecting one side of the lamp to ground and the lamp lights. The main reason I did it this way is so that with the door open, I’m not stirring up the cold air and mixing it with warm air from the room. I wanted to install one in my Norcold 982IM but the door switch was not readily accessible. In looking at the schematic of the control board, I noticed that the fan control is a negative terminal. That got me to wondering if the lamp is at 12 volts all the time and the control board grounds one end of the lamp in response to the door switch. I pulled the cover off the lamp and sure enough, that’s how it works. I was able to wire the positive terminal of the fan to the innermost terminal on the lamp and the ground was picked up on the cooling fins. Now with the door open the fan is off and with the door closed, it runs. If someone wanted the fan on all the time, just use the outermost lamp terminal. It’s at +12 all the time. The only fly in the ointment is that the +12 is supplied to the lamp at all times… even with the box turned off. I decided this wasn’t a problem for me since if I have power on in the coach, I am typically using the refrigerator. If this was a problem, a tiny toggle switch could be installed near the fan to turn it off when desired. Hope this helps someone that might be trying to figure out how to get a 12 volt fan to work inside a Norcold refrigerator.
GL Taylor User ID: 9335603	Feb 28th 4:03 PM I checked back on another bulletin board and I had asked that question on it back in September of 06. It was never answered there but with some suggestions. I will get on this tomorrow as I found that it really helped in the old Dometic and you didn't have to replace the batteries all the time. Thanks and I posted it on the other bulletin board already. Thanks again and this is why I like these boards. I have sure learned a lot on them and I have had RV's since 1990. I check out 4 of them daily and have them set up on the Desktop as Icons.
Marty in TN User ID: 8520773	Mar 1st 12:48 PM Steve: I placed a reference to your posting on the Norcold Refrigerator on another forum, got an answer back that Norcold does not recommend using a fan. Any thoughts on that comment? Marty
Steve D User ID: 1418774	Mar 1st 7:13 PM Mar 1st 7:11 PM I can't imagine why they would say that other than if they did recommend it, they might be liable to pay for it. It sure helped my last box and it is working great in this one as well. Others have posted how much it has helped their boxes so I have no worries about it. If it turns out to hurt the cooling in some way, it is very easy to remove but my bet is that it works great. On edit, as I think about it, I CAN see how it might upset the balance from the freezer to the refrigerator but time will tell. Since the thermostat is in the refrigerator section and the freezer section is "slaved" to that temperature, if the fan improves the cooling in the refrigerator section significantly, it is possible that I might have to RAISE the thermostat setting in the refrigerator portion of the box to prevent it from getting too cold. That will raise the temperature in the freezer as well but I can easily monitor the temperature in both sections and see what happens. If it turns out to not work out well, I will report on that later. I'll let you know in a few months. Steve
Steve D Moderator User ID: 8910463	Mar 10th 7:43 PM UPDATE: After a week or so of running the fan with a FULL refrigerator and freezer (we emptied the box at home before starting this trip), I can tell you the freezer is running -3 to -5 degrees and the refrigerator is running 31-33. The temperature is very uniform throughout the refrigerator which means the "cool ones" are all nice and cool. So far, so good! Steve