Ground wire issues?!?

Just replaced starter and still getting a single clicking sound without turning over. My radio and dashboard lights dim while tuning ignition also. Tested battery, full power. Thank you

 

Did you verify the engine isn't locked up?

If the engine turns then get you a helper and voltage drop check your main power and ground.

Meter set to volts DC, one lead to the negative battery post (not cable) and the other to the engine block then have someone turn the key to crank and measure the voltage.
Then put one lead to the battery positive post and the other to the main power stud on the starter then have someone turn the key to crank and measure the voltage.

If you get more than 1v drop in either of those tests then you have a connection issue in the cable or battery terminal.

 

Ok thanks ill measure voltage between today. Engine shouldn't be locked up, was just driving fine. How would I know that? seems like a bigger problem