I implemented a simplified version of the 'run forever' power cord mod on my 2720SL about a month ago. It works great.
First, thanks to 'Bill' for his excellent design and documentation which made the project possible.
I have posted some pictures on my personal webpage at
http://mywebpages.comcast.net/wbarber20/tm.mod. The pictures are my first attempt at using a new digital camera, so beware. Also, they are not of mush use without the following explanation.
I figured we only needed the 12v power part of Bill's design, so I eliminated the 120v power to the refridgerator. What we wanted was a way to keep the frig running after returning from a trip without raising the TM.
Eliminating the 120v circuitry let me cut back from a DPDT relay to a SPDT relay and greatly simplified the running of the wiring.
Here is what I did - FIRST DISCONNECTING THE BATTERY so there was no live current, 120v or 12v in the trailer.
1. Removed the necessary screws and pulled the entire power panel/converter from the wall location under the bathtub (see photo inlet.1). This gave me access to the trailer fuse panel wiring.
2. Mounted the relay on the flat surface on the back of the panel and mounted the fuse holder through one of the spare wire holes toward the left end of the A/C fuse panel (see photo inlet.2 and look closely at the left side to see the rear of the fuse holder.). The fuse location allows me to change the fuse, if necessary, just by opening the fuse panel door and unfastening the two hex head screws which hold the 120v fuse panel cover in place.
3. Outside the trailer (on the driver's side) I removed the black plastic cover which protects the bathroom plumbing. I had bought an inexpensive 10ft 16 guage grounded extension cord and cut off both plug ends. I pushed the wire up past the plumbing and toward the rear toward the vent underneath the trailer near the power panel. A lot of the trailer wiring routes through this shared space with the bathroon plumbing. The wire went right through nearly to the panel. It was easy to grab it and connect it through the fuse to the relay.
4. The wire from the converter is nicely labelled by TM and it made connecting it through to the relay easy - if you haves Bill's schematic.
5. Underneath the trailer again, I drilled and filed a hole in the frame for the male power plug inlet. I routed the wire along the top of the frame and then through the opening in frame for the torsion bars and from there into the inlet hole (see photo plug.1 and look for the black extension wire.
6. Next, I mounted a weatherproof outdoor plug cover over the power inlet (see photo plug.2 with the cover held open).
7. Last, I sealed all the wire and mechanical connections with GE RTV108 silicone rubber adhevsive. RTV108 is waterproof, it insulates and it glues every thing in place. The idea was to provide a waterproof and vibration proof installation.
TESTING:
I used my ohmeter to check all the wiring, then plugged power into the inlet to check the relay operation and turned on an interior light to check 12v power (the battery was still disconnected). I tested the 120v receptacle and the shore power plug to make sure that there was no 120v connection in the trailer. I then unplugged the inlet and plugged in the regular shore power to make sure 120v and 12v power worked as they did before the 'run forever' addition. With that complete I put the plumbing cover and the power panel back in place, re-connected the battery and started using it.
We have taken two trips since the installl, one of them over really bad back roads and everything has stayed in place and works fine.
Here is a short parts list :
SPDT relay Magnacraft 781XAML-120A (~$8 from Allied electronics).
120v male power inlet from Allied (~$1.75)
Fuse holder and 10 amp fuses from Radio Shack.
16 guage extension cord (~$3) and black weatherproof outdoor plug cover (~$4.75) from Lowe's.
NOTE: The TM is open between the powerpanel, the bottom vent and the external bathroom plumbing. I don't think there is a heat problem. In fact, I now use the 'run forever' connection to keep the battery charged when the trailer is not is use.
LAST NOTE: Wade started this thread last year when he had a 2720SL. I bought it from him last fall, so now that 2720SL has the 'run forever' mod - small world, huh??