get a NEW battery...wirebrush the lug connection of the negative cable to ground connection with a coarse wirebrush~ with restored system ground, you'll be okay then~
Ok, there's no reason to try to run your engine with one or the other coil pack disconnected. To answer your question - who knows? The system was not designed to run under those circumstances. Is there a drivability problem? BTW - NOT a Ground wire or Battery concern.
On my 1994 model, don't believe one of the two work. Don't know if that's normal, but if it's running don't worry... about to check a dealer about the issue though.
You could swap them...to pinpoint the defective voltages there~
Looking for a Used Ranger in your area?
CarGurus has 5,439 nationwide Ranger listings starting at $800.
Search Ford Ranger Questions
Ford Ranger Experts
Related Models For Sale
Used Cars For Sale