refridgerator keeps running

I just replaced the defrost timer yesterday and turned on the fridge. But I am noticing that the fridge keeps on running. The temp in the fridge is cold. I turned the thermostat down to 1 just a few minutes ago and it turned it off and the temp in the fridge is 41 degrees, but after a few minutes it is running again.

Do I need to purchase a new thermostat too and replace that also?

PS… the defrost timer instructions I got from this site with the timer said that my original model and the new one I am replacing it with had a "Version 2" match, and I put the black free wire on the no. 1 terminal according to "procedure 3"…would this of been correct?

You might have system problems. If the evaporator coils are completely defrosted, turn the fridg cold control to the lowest temperature setting and measure the freezer temperature and post.