Date:         Mon, 07 Jul 1997 08:16 -0600 (MDT)
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         BLAINE_BACHMAN%PL-01M3@ccmail.plk.af.mil
Subject:      Dometic fire alert (at least for the 182B)

     First let me admit that my experience may have been a fluke.
     
     You may recall that a week ago I described a situation which rendered 
     my fridge partially inoperative.  I was pre-cooling it on propane, 
     parked the car in front of the house, came out 10 minutes later and 
     opened the sliding door, and was greeted by a rush of smokey air (like 
     someone had smoked a cigarette or two inside with the windows shut).
     
     Anyway, the 8A fuse (behind the driver's seat) was blown and the 
     circuit was shorted.  In reviewing the wiring diagram, I surmised that 
     the fan motor had shorted out.  In order to run the fridge on 12V and 
     110V, I pulled the one wire from the three-prong plug (though of 
     course I would be running without the fan, and wouldn't have the 
     propane ignitor).
     
     Well, I pulled the fridge this weekend and here's what I found:
     
     The fan had caught fire!  The motor was there, but the fan blade 
     assembly (and all other plastic pieces of the motor) was gone.
     
     The wires were melted off and fused together.
     
     BUT IT GETS WORSE
     
     There's a 2" high portion of the wall paneling that "frames" the 
     backside of the opening; a 3" wide section of this was burned down to 
     the floor (probably as a result of the burning, melted plastic of the 
     fan blades dripping down on it).
     
     Why the whole vehicle did not go up in smoke, I don't know!
     
     THE FIX (I think)
     
     I was never too happy with the fan motor circuit having power all the 
     time, even when the fridge was not operating (it gets hot enough here 
     in New Mexico to kick the fan on when the car is sitting in the 
     parking lot), and since there didn't seem to be an "automatic" way, I 
     decided to install a switch.  And while I'm at it, a secondary fuse 
     (with a lower rating, to be sure).
     
     I had already purchased one muffin fan (cigarette pack size in Derek 
     Drew's "fridge manual") to add to the back.  I returned to Radio Shack 
     and bought another one, part # 273-243 (to make it two), plus the 
     small one 273-240 to install inside, a low profile DPDT rocker switch 
     275-695 (mounts in a 5/8" hole), a low profile panel mount fuse holder 
     270-368, some 5A slo-blow fuses (though I think I'm gonna go back and 
     get some even lower-rated ones - say 3-amp), and nylon wire ties.  I 
     also picked up (elsewhere) a sheet of aluminum, 14 gauge automotive 
     wire, some clear silicon, and shrink tubing.
     
     Examining the "control" panel atop the fridge, I found that there was 
     space for the rocker switch right were the Dometic logo was, and that 
     the fuse holder could be installed between the pump and the 
     thermocouple hold-down button.  I drilled the two appropriately-sized 
     holes using wood-boring "spade" bits at low speed in an electric drill 
     (this is THE way to drill plastic; twist drills don't cut perfectly 
     round holes).
     
     After determining the proper orientation for the fans, I tie wrapped 
     them together through their mounting holes, and then tie wrapped them 
     to the bottom of the lower set of "fins" - BTW, how hot do the fins 
     get?  Are the fins likely to fatigue the wire ties to the point of 
     breakage?  Should I figure out another system to mount them?
     
     I connected the wire pairs from the fans - oddly, the RED wire is the 
     negative and the BLUE wire is the positive - and after slipping shrink 
     tubing on the wires, soldered the RED fan wires to the fridge's BLUE 
     ground wire, and the BLUE fan wires to the fridge's YELLOW wire which 
     comes from the thermo switch.  Slid the shrink tubing over the solder 
     joints and shrank it.
     
     I opened up the cover over the terminal block and found the yellow 
     wire that goes to the thermo switch and removed it.  I then installed 
     a new wire from the terminal block to the "in" side of the fuse, a 
     wire from the "out" side of the fuse to the two center terminals on 
     the rocker switch, and a wire from one of the "on" terminals of the 
     rocker switch back to the yellow wire that leads to the thermo switch 
     (again insulated with shrink wrap).  I made sure to run the wires 
     along with others, wire-tying them as needed and keeping them away 
     from moving parts.  I now have a fused and switched circuit to control 
     the fans.  I also installed the small fan inside the fridge with 
     silicon, drilled a small hole in the top for the wires to pass 
     through, grounded the RED wire at one of the grounding terminals, and 
     extended the BLUE wire to run to the second available "on" terminal on 
     the rocker switch.  Now the switch will also control the inside fan.
     
     I squeezed silicon all around the hole where the wires go to the 
     inside fan to seal the hole and protect the wires.  I also reinstalled 
     the terminal cover.
     
     Before I reinstall the fridge, I'm gonna line the rear "floor" and 
     lower back wall of the opening with some of the aluminum sheet.
     
     Hopefully all of this work will make the fridge safer to use (and 
     leave unattended for 10 minutes!) in the future.  I think I'm gonna 
     install a smoke detector, too!
     
     Please, please pass on any comments you may have about my ideas.
     
     -Blaine