2000 150TXRY, Slow Crank when starting

[mcummings7]

When starting my motor (at all times, hot or cold) and turning the key I'm getting a slow crank. It almost sounds like it's struggling to get power. My Starting Battery is brand new and has the correct amount of CCAs. When start cold it obviously take a little longer than normal to start up. After it's warm it's starts up a little quicker but still has the slow turnover/crank. Any suggestions what this could be?
My initial thought would a starter that is beginning to fail, but before I replace that I wanted some suggestions.

[madharchod]

well it sounds like you have corrosion in your wires check that and replace them

[mcummings7]

well it sounds like you have corrosion in your wires check that and replace them

Thanks for the reply!

I will check the connections on the Batteries. The connections to my Battery switch are Brand new as is the battery switch itself.

Any other areas I should check?

[99yam40]

bran new batteries can be faulty.
pull it and have it load tested.

I have found battery cables that failed internally due to corrosion.
Voltage drop test under load should show if there is a problem

[rodbolt17]

once all electrical stuff is verified, drop the lower unit and inspect the drive shaft bushing in the mid section.