Tune up and battery light staying in

Ok I have 2 questions. 1 my alternator went bad in my truck and killed my battery. I replaced the alternator but the red low battery light won’t go off. How do I fix that? 2nd question I need to do a tune up on it the ranger it is a 4 cylinder but has 8 spark plugs. What do I need to do the tune up? Any help would be appreciated.

Install a new battery, and hope you didn’t fry that new alternator.



I did get a new battery and that light still won’t shut off.

What year Ranger?


It is a 1994 Manuel transmission

As far as your spark plugs go: that is not an easy job. Check out the videos on YouTube. The eight plugs are an oddity for a 4 cyl engine.

There’s nothing special about your charging system.

So a new battery/alternator should have solved the problem.

Maybe the serpentine belt and components are worn?



Do the spark plugs AND the wire set

It’s highly likely that one or more wires will be damaged during the tune-up, so best to have a set on hand, along with those 8 plugs

You may have to replace the alternator again. It sounds like you got a defective unit. It is very important that warning works as it supplies current to the exciter inside the alternator.

Check all cables and wires at both ends of the alternator and same with battery cables. The connectors should be cleaned properly and no corrosion or damage along the cables.

Ok I will give that a try