Charging Indicator light

[RonSerling]

Good Afternoon Ranger Fans,
First let me say I am not great with electrical issues !!!! I am an engine and trans builder and can do it with my eyes closed or in my sleep !! That said I have an electrical issue with my 93 Ranger 4.0 4X4 and I could really use some help please. About a month ago the battery indicator light started flickering on and off every once in a while, I would get home and take my volt meter and test it. Basically with the key off I was seeing about 12.6 to 12.8V and then when I start it up and check it shows anywhere from 13.7 to 14.2V Now I have been driving it for a couple weeks and now the indicator is always on when the truck is running. It doesn't seem to effect the way the truck runs but it bothers me the light is on. As I said I checked the voltages, I cleaned the battery posts and all the connections in between but I am puzzeled as to what the issue may be. So the question here is there anyone here that might be able to walk me thru the diagnostics of finding the issue or be able to tell me what other things I need to check to get this resolved ??? I really hate seeing that little light every time I am driving and I would really like to get it resolved. Any help would be greatly appreciated. Thanks

 

[4x4junkie]

The initially intermittent, but now steady light sounds to me like maybe the alternator brushes finally wore out and failed, however if that were to happen, it would no longer be charging properly. I'm drawing blanks on what else it could be unless maybe there's simply a short or intermittent somewhere in the wiring to the light.

You mentioned it's putting out 13.7-14.2V while running, which is often considered as being within limits, however it is a little on the low side of average. Charge voltage should actually be in the range of 14.8-15V when you first start the engine cold, and then as it warms up and you've been driving it for a bit, it should gradually drop to 14.2-14.4V and remain steady there (this assumes a non-depleted battery). You have verified this is still the case even though the light seems to be on all the time now? (and that your battery still has 12.6-12.8V when the engine is off?)

 

[RonSerling]

I was actually playing around with it a bit today and when I started it up it was at 14.9 for about 2 minutes then it dropped to 14.6 and held there for the rest of the time it was running, about 20 minutes more. And it is steady at 12.8 when not running

 

[4x4junkie]

That is an odd one...

Sounds like it's charging normally (14.6V is a slight tad high unless it's pretty cold outside, but shouldn't create an immediate issue with today's maintenance-free (lead-calcium type) batteries... it'll probably drop a little further after another 10-20 minutes of driving).

Maybe a piece of electrical tape over the light then? (I got nothing else other than maybe a short in the wiring to the light)