From: theise@panix.com   
      
   On Wed, 5 Mar 2025 20:03:57 -0000 (UTC),   
     Ted Heise  wrote:   
   >  On Wed, 5 Mar 2025 09:05:19 -0600,   
   >    sticks  wrote:   
      
   > >  The first place to start would be the 7 prong plug in, on the   
   > >  tow vehicle, and the vehicle being towed.  I am going to take   
   > >  it for granted most of us would be using a 7 prong plug.   
   > >  Any differences are minimal and easily solved.   
      
   > >  So let's start on the tow vehicle.  It might surprise some of   
   > >  us that our plugs don't even have power in them as delivered   
   > >  from the factory. I have an F-150 and was quite surprised   
   > >  myself that I had to install an additional fuse to get my   
   > >  line hot.  It was wired, but not fused and inactive.  With   
   > >  today's CANBUS systems, it can be difficult testing this, and   
   > >  you really have to use a 12 volt test light and not a volt   
   > >  meter.   
   >   
   >  My thinking was to take a reading from the LiIon battery app   
   >  with the battery connected to the trailer and then with the   
   >  fridge started (I think it may run off the batt for a minute or   
   >  two). Then I would connect the 7-pin to the running TV and   
   >  repeat these readings.  Does that seem like a reasonable   
   >  approach?   
   >   
   >  I need a block of time to get out to the storage unit for this,   
   >  so in the meantime I figured I'd take some measurements at the   
   >  7-pin. First I connected clips from my multimeter with the TV   
   >  off.  Surprisingly, I got some sparking, may have been from   
   >  touching across pins.  But once I had a good connection I got   
   >  no voltage.   
   >   
   >  Now this could be from the line not being hot (e.g., because of   
   >  a fuse needed), or because a multimeter won't work.  But I   
   >  vaguely recall having gotten a 12-13 V reading from the pins   
   >  some time in the past.  So maybe the sparking blew the fuse.   
   >  I'm trying to run down where that would be and will let you   
   >  know what I find.   
      
   Okay, I found the fuse (designated "trailer battery") and found it   
   was definitely blown.  Put in a replacement, and still get no sign   
   of 12 V at the proper pins (at about the 1:30 and 7:00 positions).   
      
   So I guess next is to ask the dealer to look at it.   
      
   Might look for a test light too, I guess.   
      
   --   
   Ted Heise             West Lafayette, IN, USA   
      
   --- SoupGate-DOS v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)