starter solenoid and/or cranking motor ??

My 52 Buick won't start. It's straight 8, 6 volt, and generator. I've done some testing and I'm pretty sure the starter solenoid switch is bad so I've already ordered one. I'm trying to figure out if the cranking motor is bad too so I can replace them both at the same time if needed.
My question... when I connect a cable directly from the battery to the starter, shouldn't it begin cranking? Right now I get nothing at all, no action, no noise. The battery has a good charge. Did my solenoid and starter **** out at the same time or is there something I am missing? Any other tests I can try?

 

if its 6vpos.grnd running a cable from the -post to the starter schould spin the starter motor hook your cable to the starter first and jumpthe post on the battery so you wont arc weld the end of the threads on the starter post good luck...steve

 

Sorry, I forgot to mention it's 6 volt negative ground. I've been running the cable from the positive post of the battery to the starter, with no results.

 

that being the case I think you need a starter...steve

 

one more thought and Ill shut up after you pull the starter hook a set of jumper cables to it again hooking the battery last if it dont spin then you for sure need a starter.I say to do this cuz its possible the starter gear is jammed against the flywheel and the bendix cant go back in the starter but if I were bettin Id say its time for a new starter...steve

 

Those old starters (and probably new ones too) had graphite brushes with springs which held them against the commutator portion of the starter armature. As the graphite brushes wore down, the spring would keep sliding the brush foreward to maintain contact.---I have seen it on old cars that sat for a long period of time, where the brush would stick in its supporting sleeve, and the spring wouldn't be able to push it against the commutator, and the starter would be "dead". A couple of smart raps with a hammer on the starter case near the *** end of the starter may free up the brush and fix things.

 

I can move the spring and plunger by hand so they don't seem locked into place. I included a photo of a diagram. I just spent an hour trying to resize it. Hope it shows up ok.