Well now you really have to fix it. So it doesn't come back to haunt you again years from now!;D
Speaking of grounds, you can go a long way towards a happy electrical system if you add a couple of your own.
First, verify that there even is a ground from the battery to the body. Ford did it, but most people that replace the negative battery cable never replace the body ground, thinking the engine ground is enough.
It isn't always.
Then, when you've made sure there is at least a 10ga ground to the wheel well, add another one between the back of the intake manifold and the firewall.
This is actually very important for your dash and windshield wiper functions.
You can double-down on things by adding another good sized one between the engine block and the frame, and the body and the frame, but the first two are the most important.
And last, but not least in importance, when you feel like getting all flexible, add another short jumper from the body (usually the firewall where the engine-to-firewall ground is) to the dashboard. This will ensure a good ground to your instruments and lights.
From the factory, Ford relied 100% on the body having good bonding/contact with each other part, from the front grille to the tailgate. This worked fine when things were new. But now, not so much.
Good luck. Just a few more things you can do standing up. Before you have to twist down under the dash again!
Paul