Battery light on

[craig sargood]

Hello everyone, noticed my battery light was on the other day and today. Would I be correct in figuring my alternator is probably the issue?? It is running 13.5-14.1. Any ideas?? Thanks

 

[craig sargood]

Also noticed it up around 14.6 the first time.

 

[Don Hall]

Could be your battery is failing. How old is the battery? Your amp readings indicate the alternator is working. Take the battery in to most auto stores for a free charge/load test.

Any reading above 13.2 V is your alternator production. In theory, a fully charged battery can read 13.2 V.

If the battery checks OK, then check the alternator.

May help (?) : https://archautoparts.com/why-is-th...-turned-on-5-step-diagnostic-checklist-video/

 

[craig sargood]

Battery is only 1-2 yrs old, was a cheaper battery. And I also have solar charger to keep battery up, and it starts up with no problem.

 

[Don Hall]

If ¥ou have volt/ohm meter, connect it to your batt, engine 'off': take a reading.
Should be above 12.5V. If not, batt is low charged.

Next, keep meter connected to batt, start engine: should read 14+V.
If so, your alternator is working. If the reading is above 13.8V, then batt light
should not be on. Could be a faulty circuit to the batt light.

Check batt connections for tightness, check condition of batt cables, check for corrosion on posts (clean if necessary).

With your starter motor responding at start-up, sounds like your batt is OK.

Does the batt light ever go 'off' with engine running?

Have you charged the batt?

 

[1970Maverick]

Take it to Auto Zone, PEP Boys, Advance Discount or any other auto chain, they usually have a load tester and check it for free.

 

[craig sargood]

I only drive this like 2-3 times a weeks, and usually not very far. I didn’t notice light go out. Everything seems to be working normal, except light is on. Also, not sure if this had anything to do with this, but I had a cheap breaker fuse for my stereo amplifiers pop the other day, tried to reset and didn’t work, replaced with a better quality breaker, and now everything is working. I’ll try some testing tomorrow morning and see what I come up with.

 

[craig sargood]

So, this morning went over to check on this whole battery light issue. After I started my truck this morning, light was on, went off a few minutes later. Checked battery with engine off (12.0v), with alternator running(12.9). Weird that it starts up with no drag. I work on this at my trailer storage, so driving there, listening to stereo, I have 4
Amps, and they went into protection 2 times. Never happened before. When I got to storage I really turned it up to see what was happening when I was looking at the amps. They went into protection 1 more time, then worked fine for like 30 minutes, thumping away. So I had a old alternator that I had replaced with this high amperage one, replaced it, and it seems to be working, 14.1-14.3 with engine running at battery now. Does anyone think that with that old alternator having issues that could have thrown amps into protection?? Never happened before, system was cold, I’ve ran this system for hours driving in 100 degree heat, no issues until this. No popped fuses except for the very first time. Installed a much better quality breaker for amp power.

 

[Don Hall]

From your readings, the batt is low. It's no wonder the alt reading is low, and the batt light is on. Don't try to charge a low batt with the alternator. The alt is a maintainer. (Yes, it is technically a charger.) Use a batt charger, and not a trickle charger, to charge the batt.

You need to start your analysis with known/confirmed readings. Working with a low batt doesn't help anything. Charge your batt until you get at least 12.9V. If your batt
doesn't reach a high level of charge, get a new batt. A fully charged batt should read 2.1V to 2.2V per cell X 6 cells = 13.0V+.

With a fully charged batt, your alt reading should be 14V+ (eng on) after a short
(5-10 min) recovery from using juice for the starter motor.