Truck Repair: Engine wont roll over, intermittantly, ground cables, battery cables

Question
I have a 1988 chevy V3500, 7.4 liter TBI 1 ton dump truck with a 4 speed transmission.  I have an intermittant starting problem where the engine won't roll over.  When I turn the key I hear a solenoid kick in which I suspect is the one which parallels its  two batteries for more cranking amps to the starter.

It has a 4 yr old rebuilt starter in it so I don't think its a solenoid and as I had this problem prior to the new starter.  Further, I think the clutch starter lockout switch is OK.  Any ideas?  

Thanks Pete

Answer
Hi Pete,
I have never heard of a solenoid that parallels the batteries. They are always parallel, and connected to the starter, unless someone has added something.
Just make sure all the ground cables, and battery cables are clean and tight. Clean to Bare metal in the battery cables.

Van