I finally tackled this project. These are some tips for working on the 2nd (optional) refrigerator/freezer.
I needed to correctly charge the system and replace the fan. Here’s a couple of key leanings:
1) At first I was looking to remove the bench top under the settee. It appears this is not possible as it is with the other (standard) unit without great effort. It is much easier to remove the unit and pull it up through the cut out.
2) Before doing any work on the unit, place a towel under the freezer (between the freezer and the hull). This will prevent anything you drop from being permanently lost under the freezer. Ask me how I know this.
3) The unit is fastened with four 10mm nuts. These do not need to be complete removed, just loosened. The nuts are very difficult to see and access with a socket wrench, but it can be done.
4) Use two adjustable wrenches to disconnect the compressor unit from the evaporator. The quick connect fittings have valves and will maintain the refrigerant. They are hand tight with just an added 1/8 turn with the wrench. Do not over tighten these when re-connecting. The quick connect fittings contain o-rings. Mine were in good condition so I did not replace or size them. (part A040204)
5) Disconnect the 24 vdc +/- power and thermostat. The thermostat wires are labeled “T” (Blue) and “C”(Brown). Note which wire is which.
6) At this point the unit can be lifted up out of the cut out. The unit is hung on the wood mount. Lift the unit and pull away from the mount.
It turned out the fan on my unit had a cracked fan blade causing it to wobble. In addition, the plug on the side of the compressor had some erosion (this is a common issue on older units and causes intermittent operation of the unit). And, it appeared the electrical box was not operating correctly. I decided I would be better off replacing the entire unit for best reliability.
I ordered an exact replacement Frigoboat, Model AV35F, Vertical Air Cooled Condensing Unit, 12/24 Volt from Go2Marine.com. The size, mounting holes and connections were an exact match. The in-line 7.5 amp fuse is no longer in the electrical box and needs to be added to the + power supply line.
Since I did not replace the evaporator, once I had installed the new compressor and made the connections, I put a vacuum pump on the system to remove all the R134a refrigerant from the entire system so I could correctly charge the system. Here’s a link to an article describing this procedure: http://coxengineering.sharepoint.com/Documents/Recharging%20a%20simple%20R134a.pdf
Note: Never connect anything to the high side of this unit. Testing, adding or removing refrigerant should all be done on the low pressure (suction) side.
Adding the correct refrigerant level is an observation science. It will take the best part of a day to add some, watch and add some more. The above article is very helpful. The pressure reading on the gauges only gives a start point. I suggest you start with R134a pressure at 10-12 lbs once the compressor unit has run for about 30 minutes. This is about 10 oz of R134a. Then the system must be fine tuned. The gauges do not help for this as each system is a little different. My system seems to be operating efficiently at 8 lbs. Yours will be different. Look at the evaporator to determine the frost line.
Here is another resource for information: https://frigoboat.wordpress.com/
Hope this helps.
I am servicing the 2nd optional refrigerator/freezer under the dinette seat. This is the one that is located under the most forward seat (backing onto the forward head). I am having trouble figuring out how to get full access. All I have is a 1 ft square panel that lifts out.
On the other unit, the seat bottom lifts up and it is easy to access the AC and refrigerator/freezer units. It there a way of taking up the seat bottom on the other side to access the 2nd unit more easily. I can see some screws in the mahogany wood paneling that wraps the unit/seat. I have removed these but it looks like the wood is glued.
Is there a better way to access this unit?
With best regards,
Super Maramu 2000