I meet every qualification for the 2000 child tax credit but TT is onlygiving me the smaller additional child tax credit??

 Not everyone is eligible for the full Child Tax Credit or the full Additional Child Tax Credit.  

If you look at line 11 of your 1040, your Child Tax Credit cannot exceed that number.  So, if your tax liability is only $1,000, that is the maximum Child Tax Credit you will be eligible for.  If it is zero, then you would not get any child tax credit.  This is a non-refundable Credits and will only reduce your tax liability to zero.

The Additional Child Tax Credit is refundable. The refundable portion is approximately 15% of your Earned income along with a few other calculations.

https://www.irs.gov/publications/p972

Overriding anything in TurboTax is generally NOT a good idea.  If you do override, you will need to print and mail your return as it will not allow you to e-file.  But to override do the following:

• Click on Forms
• Go to the left-hand side of the screen and click on the child tax credit form right click on the number you want to change and click Override, type in the new number
• You will need to do this on schedule 3 and 1040 as well

Prior to overriding, please look at pub 972 (link above) to verify that you are not changing numbers that should not be changed.