Like many others on the forum I have been very annoyed with the noise that the cooling fans make on the Dometic Refrigerators that are installed in slide outs. After reading several posts on the forum about the noisy fans, I ordered two Gelid FN-TX09-20 Silent 9 TC 92 mm 2000RPM fans and installed them this weekend. Ended up taking me several hours over two days to finish the installation but that was primarily because of trial and error. Now that I’ve done it once, I could do it again in a matter of a couple hours tops, if not quicker. So to save others time, I decided to post a step by step installation process with pictures.
First of all you need to remove the upper refrigerator vent cover. You will immediately see a piece of thin wood that covers the majority of the opening except for the top few inches. You will need to remove this partition to access the original fans. You can either completely remove the wood, as I did, or use a sharp utility knife or small saw blade to cut out the center section as one forum member did. Be warned, that if you choose to completely remove the partition, it’s a bit time consuming to remove all the calking that was installed at the factory.
Once you removed the partition or a section thereof, look down at the back of the refrigerator. Approx 6-8 inches below the lower edge of the vent opening you will see two computer fans. Trace the red and black wires from the fans to the white plastic quick disconnect connection on the left side of the opening. Disconnect the two wire connectors (one for each fan). The other side of these connections goes to the thermo-coupling that signal the fans to turn on when the cooling fins get two hot.
Use a Phillips screw driver and undo the two screws securing each fan to the back of the refrigerator and remove the fans. The original Sunon fans turn at 4500 RPM and push a lot more air than the Gelid fans at 2000RPM. Therefore I choose to re-position the Gelid fans up higher and closer to the cooling coils. Since there was no place to mount the fans on the back of the refrigerator higher up, I made some brackets out of some old hard plastic that I had and attached them to the outer wall board (see pictures). You can use plastic, thin metal or even thin wood to do this; whatever you have handy.
When you go to plug your Gelid fans into the existing wiring harness, you will note that the plugs are not compatible. The Gelid fans come with a three pin harness and the original fans have a two pin harness. Through trial and error, I discovered that the yellow wire on the Gelid fans is not necessary for this installation. Take the original fan wires and cut them approx. 6 inches below the plug. Cut the three pin plug off of the Gelid wire harness. Using either butt end connectors or wire nuts, connect the red and black wires from the original plug to the Gelid fan’s wire harness red and black wires. Do not do anything with the yellow wire on the Gelid’s wire harness.
At this point you can either install the Gelid fan’s in the Sunon fans original location on the back of the refrigerator; or attach them to the new brackets you fabricated to mount them on the outer wall board and then screw the brackets into the outer wall board. If you do make new brackets, make sure to test fit them to make sure the fan does not make contact with the back of the refrigerator. If the fans touch the back of the refrigerator, they could cause a vibration when the fans run even more irritating than the sound of the original fans running. After installing the new fans, reconnect the plugs and then zip tie all the loose wiring so it is neat and snug. Before replacing the partition, turn on your refrigerator and take a hair dryer and or heat gun, on low, and heat the thermo-coupling to make sure the both fans come on and operate without any noise, etc. If everything checks out, replace your partition.
Due to the fact that the Gelid fans do not push as much air as the Sunons, I did not re-calk my partition at this point. We are going camping later this week and the forecast is for 95+ degree weather. So I’m going to see how these new fans work first before re-calking. If need be, I’ll add one or two more Gelid fans. I’ll report back after the trip to let everybody know how the Gelid fans do. However, I can report now that you can not hear these Gelid fans running! Before getting into the pictures, there is a 4 amp automotive style fuse in line with the fans. I highly recommend removing this fuse before you start any fan/wiring changes as it is very easy to blow if you cross wires. (Ask me how I know) After your new fan/wiring installation is done, then replace the fuse before you do the hair dryer/heat gun test.
As you will see in my pictures, my thermo-coupling is already mounted on the outside edge of my cooling coils. Based on some posts that I've read, apparently some were not mounted like this. However, Dometic has recommended mounting it on the outside edge to limit frequent cycling of the fans. Lastly, I also ordered the Dometic cooling fans for inside the refrigerator and from the posts I’ve read, this really seems to help in keeping the refrigerator cold on hot days: Dometic Evaporator Fan Greater inside Cooling Deluxe Model - RV Cooling Unit Warehouse
NOTE, IF YOU CHOOSE TO MOUNT YOUR FANS ON THE OUTSIDE WALL, AS I DID, IF YOU EVER HAVE ANY WORK DONE ON YOUR REFRIGERATOR, MAKE SURE YOU TELL THE TECHNICIAN TO DISCONNECT THE FANS BEFORE PULLING THE REFRIGERATOR OUT FROM THE WALL.
Pic #1 is one of the original fans.
#2. is the original fan connecting plug
#3. is the Gelid original fan connecting plug
#4. after the Gelid wires are spliced to the original wiring plug
#5. fan mounted to fabricated plastic bracket
#6. two new Gelid fans mounted, wired and ready to go.