Help with installing a new input jack?

Likely going to need a better image of the new jack and wires from the side.

Do you own a volt-ohm-meter?

 

Yes, it's hard to see if there is any issues from here. You are dealing with only 3 wires, and if you've followed the wiring from one jack to another, there should be very little to go wrong.

Try touching up the solder joints and trim the ends of the wire sticking through the hole on the tab. I once had a wire tab actually touching the sides of the hole where the output connector was installed. I spent an hour trying to figure out an intermittent signal problem on a bass until I realized that the signal wire was touching the shielded sides of the very tight-fitting hole. Simply trimming the wire back a touch, as well as a very slight bending of the tab inward solved the problem.

 

You would be better off installing an output jack.

First, it looks like you are using the wrong kind of jack, on two counts. How are you going to mount the new jack? The new open frame jack will require a different mount on your bass. But even if you have the mounting worked out, it looks like you have the wrong type of jack - your new one is a mono jack and you need a stereo one, which looks like this:



The black wire is from your battery. The other two are from the preamp - one will be ground (check the documentation for the preamp) and it goes to where I have the red wire. The third wire is the output from the preamp and it goes to the green point.