Starting Problem

[Alle007]

After my rig sat for 2 weeks at a shop, it came back with a starting problem. It used to crank over, two pushes on the gas pedal and started right up. Now, when I turn the key, lights come on but does not crank over until i turn the key back and forth really fast, back and forth quickly. Then it starts to crank and eventually starts up, but seemingly almost not.
Does anyone know where this is coming from? or what it could be?
When I got my rig back the battery and two deep cycle marine batteries hooked in series where all dead and needed to be charged before attempting to start it.
Thanks

[twinboat]

Classic sign of a sticky starter mounted solenoid.

First check all of the battery connections, positive and ground.

A test for a sticking solenoid, would be to have someone hold the key in start position and then tap the solenoid on the starter.
If it starts cranking, you need to pull It and change the solenoid or the whole starter.

[Alle007]

Right on, thanks twinboat!