Technical Battery light issue

[Adamwill]

So my daughter's 2017 Fiat 500x 2.4L alternator went out. I replaced the alternator, serpentine belt, and battery. No battery light is on. I checked all the wiring and replaced fuses. Can anyone offer advice on why battery is still on? Car started right up and runs fine but I know there could be an underlining issue that could get worse later.

 

[arekp]

Have you searched the forum?

Are the battery terminal connections tight?

Have a look here.

 

[s130]

When you say "No battery light is on" did you mean "Now battery light is on"?

Battery light should be on till engine starts and runs.

Don't know specifically about the 500X alternator but usually there are at least 3 connection. Ground, +12V and a "Sense" wire. On some alternators the sense wire has just a simple Lucas type female spade connector which can be difficult to correctly fit.

 

[Adamwill]

When you say "No battery light is on" did you mean "Now battery light is on"?

Battery light should be on till engine starts and runs.

Don't know specifically about the 500X alternator but usually there are at least 3 connection. Ground, +12V and a "Sense" wire. On some alternators the sense wire has just a simple Lucas type female spade connector which can be difficult to correctly fit.

Sorry. Yes I did mean now. I get all lights go through a start up check when car starts but the battery light stays on. I checked all connectors last night but still remains on.

 

[Adamwill]

Have you searched the forum?

Are the battery terminal connections tight?

Have a look here.

I rechecked both terminals. They are tight and clear of any corrosion.

 

[s130]

Put a volt meter across the battery terminal. Actually chassis ground and battery +ve as the 500X has monitoring unit between battery negative and the chassis ground.

Measure voltage with engine OFF. Probably around 12V

Started engine. Voltage should go to around 13.7V to 14.7V.

If not then the new alternator is not getting charge to the battery.

Repeat test but this time at the alternator/chassis and the alternator +ve output.

Compare results.

 

[silvanu96]

The charging error (red light battery) must be diagnosed and cleared.
There is intelligent control of the alternator by the computer, thats where the error is.
Right now the alternator works in safe mode , but works.

 

[Mike1alike]

Yes. You need to erase the stored error in ECU.

 

[kirbyjohn601]

If the battery light is still on after alternator + battery replacement, but the car runs fine, this is usually not a charging failure.