Alternator/Battery issue

[BeastFordGirl2016]

1996 Ford Explorer 4X4 [My Beast]

So I just replaced my alternator. I thought it needed replaced when I bought the truck almost a year ago but turned out I needed a new fuel pump. Anyway, I also replaced the battery last year even though it was only a year old. Fast forward to now. After we changed the alternator, the truck ran fine. Today, (exactly a week later) the truck won't start and it's making a ridiculous clicking noise. Started with a jump, but will this continue? Do I need a new battery? What else could be fixed ? The light on my revs (on my dashboard) also don't work as well as my 3rd brake light.

 

[1998Exp]

You may have a bad battery, or a bad alternator. You may also have rotten cables, which would be the first thing to look at - including under the insulation. Check the battery clamps and the negative (ground) connection to the engine block. If those are OK, get hold of a multimeter and check if the alternator is charging. You should see 13.5-14V at 2000 RPM or so, with the headlights on. If that's OK too, it's probably the battery not holding charge or having a shorted cell.

 

[J_C]

Sometimes an alternator will be half working before it fails and keep the battery perpetually drained too much, which will wear it out quickly even if recent/new. You can use a multimeter to see if the alternator is putting out around 14.4V once the engine has been running for a few dozen seconds (the wait is only needed because the battery is probably drained).

If it is putting out in the 14V range then it's probably fine, take the battery to some place that can test it. Technically this kind of *abuse* shouldn't be covered by a battery warranty but you might have one that will get you a pro-rated or free replacement battery depending on exactly how long ago you bought it. First I would check for corrosion on the battery cables, take them off and clean any off if present.