Battery light on dash on

Sounds like you have an alternator showing the early signs of failure.

Alternator is just about done, friend had his 2012 Ford 3/4 just about burn up last week, same problem, lucky to catch it in time, a lot of the wiring back of alternator was burned off.

FIrst thing I would do is check to make sure the alt belt is still there and tight.

Considering the next day numbers I would clean the battery posts, alternator terminals and just keep an eye on it. If the alternator does fail, rather than a hiccup, you can keep the coach going while on the road by running the generator which will cross connect to the chassis 12VDC system and keep the engine running until a replacement can be found.

Replacing is pretty easy maybe an hour job. With a bit of searching for a Ford Commercial Truck service center, any independent place that can handle a F-53 based coach or even a mobile tech along your travel route you can make arrangements for replacement. You could even buy a replacement now (which will guarantee the original will fail) so all you will be looking for is someone with tools and knowledge to swap it out.

The V10 has one wide serpentine belt with an spring load slack adjuster that drives all the engine accessories. If there was a problem with either good possibility you would also overheat or the A/C would be also acting up or the power steering and power brakes would be misbehaving. Power brakes are not vacuum driven but use pressure from the power steering pump to assist with braking.

Except for checking the belt, ALL of this is just shooting in the dark without having a meter to check the actual voltage.

I would also Load Test your battery. It’s free at most auto part stores.

The Battery light is not really a battery light. It indicates the alternator is DRAWING more power than it is generating (usually at least) this can happen if the engine speed is too low.. The alternator gets wet (I used to have a car that did that if I hit a puddle big enough) Wires break or come loose or .. A

As others have suggested.. Failure.

wa8yxm wrote:
It indicates the alternator is DRAWING more power than it is generating

Except in a case of a total failure, the alternator does not "draw" power.

The light indicates that the whole 12 V system is drawing more power than the alternator can replace in the battery......and has been that way for more than a few minutes.

It is probably just a "low voltage" light and usually indicates that the alternator has been putting out nothing or too little for long enough that the battery is getting low.

Alternator is telling you it's about done and/or the internal voltage regulator. If I were you, I'd replace it, the serpentine belt and a new starting battery because the battery has been covering for your failing alternator fir a while now.

Idiot lights are just that. Idiots.

Agree that alternator is likely problem ... but if your batteries are SOL then that might place your alternator under stress as well. I would have both checked out.