electrical power loss

[Hook n ladder 1]

I had weird problem the other day.  I just left the yard and a block down i lost all electrical power.  She was dead as a door nail for about 2 minutes.  All power came back and she started fine.  I did check all connections and they were tight.  Got going again and another block down she lost power again.  Same thing again.  Few minutes later powered back up again.  Limped back to the yard.

I did something a few days prior that I didn't think would do anything.  On my batteries i have one of those 3 terminal power cables with a stud on the top of it to connect the positive cable to the truck.  I always used this top stud but moved it because it doesnt let the battery box cover sit flat (it's covered so the metal stud doesn't come in contact with the metal box cover). So I moved the positive cable to the middle battery stud and then put this three way power cable on top it.

So I switched it back and haven't had a problem. All batteries tested good.  Can someone tell me what happened?  

thanks.

[Freightrain]

Not sure what that 3 cable thing is?  A picture would help.  

Im guessing a later model truck?  Sounds like it was losing battery power, thus shutting down.  Must have lost alternator line too due to that bad connection.