Hello. I am new here as I am in need help ASAP.
I'll start by saying that I am mechanically enclined and have all tools necessary.

So I bought a 2004 Chrysler Sebring Limited Comvertible with a 2.7L V6. 170k miles.
Previous owner told me that the battery died a few months back and he bought a new battery from Walmart and ever since, the cranking seamed week. So I figured that maybe he got the wrong battery or doesn't have enough cranking amps.
Drove it home and that night I went for a drive. The street I was on was a long straight road (residential streets). I noticed that the diles on the dash went down and the steering was tough. The car had died but all the dash lights were on. Didn't have a radio so that's out of the picture. Pulled the car down a street and parked it. Tried cranking it over but the starter seamed very week and would crank one or 3/4 rotation and click. Still all the dash lights are on.
I got my girlfriend to come pick me up and bring jumper cables.
Tried giving it a jump and still nothing. The next morning I bring my car and tools. Checked the colts before doing anything and read 12volts. Tried starting it and nothing. Then tried jumping it and nothing. Tapped the starter and still nothing. So since the starter didn't seem to difficult the remove I decided to remove it. I took the battery and the starter to Oreilly and have them test. The starter spun but the gear was not pushing out/ engaging. The battery did not have enough to cranking amps so was garbage. After 3 months??
Since my intentions were to flip the car, I was not looking to buy a brand new starter. I bought a brand new battery and went to the nearest Chrysler Dismantler for a starter. I took the new used starter to Oreilly and tested good.
Installed along with the new battery and still nothing. Did a tad better as it would do 2 very week and sluggish rotations and nothing.
At this point I'm lost because the car died in the first place and now is having a starter issue.
So I checked fuses.... Good.
Checked relays by switching with the misc relays that knew worked and nothing.
Checked ASD relay and nothing.
I was thinking that maybe low compression such as a blown head gasket but the car never overheated.
Oil and coolant were not contaminated.
I'm thinking that maybe the battery is putting out to much power or too little causing the alternator to fail causing the car to die and putting out too much or too little to the starter.
Tomorrow I will possibly try using a new starter.
Before doing that I will check the battery cables and from what I've read on here, #8 Fuse.
What are the necessary amps or volts needed for the starter to crank normally?
How do I check? I have a voltmeter.
Any suggestions on what else to check?
I never liked doing electrical work but now I have no choice.
Thank you everyone and apologies for the long post. Trying to go into detail.
Oh and one more thing, installed the new used starter and tried turning it on One sluggish rotation and a second and held the key still to see if anything Would happen and the starter started smoking????? I don't think this is normal, maybe it'll lead to something.
Thanks again
-Paul

 

smoking means its drawing to many amps you have an internal engine issue like a bad bearing or water pump went out and flooded the crank cases with coolant.
Use a breaker bar on the crank bolt turn it by hand. should be able to move it with out to much effort when the compression leaks down U can also remove all the plugs and should turn real easy if not yeah internal engine issue.

 

I drained the oil and didn't see any coolant contamination or metal shavings (which would probably be in the pan).
Tried turning the crank shaft with a beaker bar and it would not budge. So I pulled the 3 spark plugs toward the front of the engine. The crank pulley still had a hard time turning but was able to get it to move a tad. I then tried to crank the engine over and was able to get a couple more rotations but still sounded weak.
I then pulled the last 3 plugs. Turned the crank and was able to make a full rotation. It felt like something was binding, it was pretty tough. Turned the engine over and a couple more rotations. The engine cranked more without the spark plugs but still sounds just as weak.

Do you think that maybe the timing belt broke and jammed the crank? I know that if a timing belt does brake then it cranks extremely fast and this is doing the opposite.
Thank you

 

2.7 is chain driven not belt

 

Damn, well I guess that's out of the equation. Let's say it is the engine main beating, think it could be done/ accessed by dropping the oil pan?