RV Repair: suburban 12v furnace, ducted furnaces, mechanical skills

Question
  I am having trouble with both furnace units in my 86 Fleetwood Southwind.  I've had the rig for a year and a half and finally got around to using the LP system.  Filled up the tank and have good action from the range.  Tried turning on the furnaces, I didn't realize until now I had two!  I'm getting zero responses from either.  No clicking, no burning, no fan, no nothing.  I checked the fuse in the main panel looked good changed it anyway and made sure the fuse was getting good contact.  Still nothing.  After looking both units over and checking out catalogs with pictures I believe they are Suburban model NT-S series ducted furnaces.  Any ideas on where to start would be very appreciated.  I don't even know what the names of the components are, but I am very handy.  I worked my way through flight school as an automotive mechanic, so I have tools and basic mechanical skills.

    Thank you very much,
       Greg

Answer
Greg,
The first thing to start with is to make sure the on/off switch on the t-stat is in the full on position,If they are and still nothing remove the thermostats from the wall and twist the two wires on the back together. This will tell you if the T-stats are bad. You should get a fan about 30 seconds after connecting the wires. If you have a test light verify that one of the t-stat wires has 12v DC power present. If you do then you will need to remove the furnace.NT series furnaces are not serviceable without removal from cabinet.Any further repair from this point will get a little more involved.Try the first steps. Also make sure you have strong batteries or are plugged into 110v for power.

Thanks, chad