Intermittent starter - no crank

hey looking for help please somebody, we have a 2012 Chevy Tahoe it was an old police SUV, So far it's been amazing unfortunately we were having issues and we thought it was a battery I went to AutoZone they tested it and they said that it was a bad battery.

replace that and then it still wasn't working, for s**** and giggles though I had one of those battery jumper things and I'd keep playing with it and sometimes it would work so believe it was an issue with the starter, Because after the charger was on it, The indicator would go from a quarter up to half and then after turning it a few times it would kick on.
well we replace the starter on Saturday, Saturday Sunday, Monday, Tuesday went a couple different places yesterday.
we had no issues at all.
this morning my fiance went to go to work and it wouldn't start.
I hit the starter with a hammer kicked on started going.

So again it work for several days I didn't have money to get the best damn starter I just wanted something in the meantime till I have the money to get a better one.

when I look through the wheel well I can see the quick connect on the starter I can see some bear copper wire it's nice and shiny so it's not like it's completely corroded yet could that cause it?

...um, ok...

So what are the symptoms?

Sounds like a "no-crank", but not sure on your description? If you hit the starter and it cranked and fired, then that's your problem. Where did you buy it? Does it have a warranty? You probably got a defective unit. Take it back.

BUT before you do that, check your cables for corrosion also, especially if you live in the rust belt. IF you live in the rustbelt, you must also do a voltage drop test because the cables up there tend to corrode but they pass a visual inspection due to the insulation looking fine.

I hope this helps.

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please. If we can't see it, it does not exist.

You are already receiving sage advice from the knowledgeable folks on this Forum.

As @strutaeng recommended, check your positive and negative battery cables, your cables to the starter (particularly the larger one), and your alternator cable AND connections. If there is any question regarding the condition of the cables, replace them. Loosen, clean thoroughly, and reconnect all cable connectors, even if they look clean and tight by visual inspection.

Last, inspect the ground strap from the motor to the firewall, and loosen, clean, and tighten the end connectors, as this is the return path for the starter motor power loop.

Then, if the issue continues, replace the starter with a GM or Bosch starter.

Check the main ground from the battery to the front passenger cylinder head as well. That one causes no start clicks if it is faulty.