Ford Repair: Ford F250 1977 4X4, fool proof method, ford 400m

Question
I have a Ford 400m.  I think I noticed that when there is moisture in the air (I live in Wahington State)the truck does not want to start and when it does it runs really rough for awhile.  I am not machanically inclined so this is an observation.  Am I correct in assuming that moisture could affect the motor and if so what do i do about it?

Answer
Dan-

  If moisture is causing the problem, you're most likely issue is bad spark plug wires.  Over time the insulation can wear down and, since electricity likes the path of least resistance, it can arc between wires given the right conditions (i.e. heavy moisture in the air).  A quick way to check this is to find a dark place or wait until nightfall and run the engine (make sure it's in as dark a place as possible).  Pop the hood and take a spray bottle with some water in it and set the nozzle to mist.  Spray a fine mist of water around the area of the plug wires.  If they're bad there's a chance you'll see little arcs of electricity jumping between plug wires or a wire and the closest metal object.  This is why it needs to be dark...it can be hard to see.  This isn't a fool-proof method, but it usually works.  Hope this helps.

Steve