Battery light on dash on

[dsisemore1]

I have a 2016 Tiffin Open Road with a Ford F-53 chassis. My battery light on the dash came on. I turned the vehicle off and turned it back on. The light came back on after about two minutes and stayed on for a couple of minutes. I stopped to get gas and once I got back on the road I drove about 5 miles the light did not come back on. I did have the generator on don't know if that matters.
I checked the battery the next day and it read 12.5 volts. I then cranked the unit and it read 14.35 volts. I turned on lights, A/C and the voltage stayed at 14.35 volts. I also started the generator but the light did not come back on. I am ready to head out on a long trip and am a little concerned. The owners manual said to bring the coach to a dealer if the light comes on. But don't want to unless absolutely necessary. Any insight would be helpful.


***** Update - Thanks for all the input. Decided to bring to Ford shop, final verdict - Light would not come on of course. They ran all test and could not find out why it happened. Everything checked out so back on the road.

[dougrainer]

tderonne wrote:

PaulJ2 wrote:
Battery light will come on also if the PCM thinks the voltage is too high.
Maybe with generator running while driving causing this.

FINALLY!

This is probably it. If the coach is set up to charge the chassis battery while parked, that same setup will try to charge the battery any time the generator is running. If the voltage it's applying is greater than the alternator voltage, you'll get a light on the dash.

BINGO, The dash light will show fail if the voltage is too LOW or too HIGH. With the Genset ON, the chassis system is reading the slightly higher Converter/Inverter-Charger bulk charge voltage which trips the chassis system to send a fault. A quick way to STOP the problem when the Genset is ON in transit.

1. Do NOTHING. In 30 minutes it will go off once the charge rate from the genset drops
2. Turn on your Headlights and Dash AC and that higher amp draw will drop the voltage to lower levels and turn the light OFF.

There is a FIX for this problem. You install a Bosch relay to disengage the dual charge (chassis/Coach) battery combine solenoid when the Genset is running. When the Genset is OFF the solenoid functions as designed. When you have the Genset ON in transit, you do NOT need the Chassis Alternator charging the coach batteries. The inverter/Charger(or converter) supplies the batteries with the recharge. Doug

[tderonne]

PaulJ2 wrote:
Battery light will come on also if the PCM thinks the voltage is too high.
Maybe with generator running while driving causing this.

FINALLY!

This is probably it. If the coach is set up to charge the chassis battery while parked, that same setup will try to charge the battery any time the generator is running. If the voltage it's applying is greater than the alternator voltage, you'll get a light on the dash.

[PaulJ2]

Battery light will come on also if the PCM thinks the voltage is too high.
Maybe with generator running while driving causing this.

[Sam_Spade]

theoldwizard1 wrote:

If the battery light is on a STAYS on after multiple re-starts and driving, then you DO need a new alternator.

12.5V on the battery after resting overnight and before starting is a little low. I think I would be more concerned about that !

That strikes me as an odd thing to say.

You would be more concerned about a battery that is just a little bit low on charge......rather than be concerned about an alternator that likely is DEAD ???

[theoldwizard1]

wa8yxm wrote:
The Battery light is not really a battery light. It indicates the alternator is DRAWING more power than it is generating (usually at least) ...

Not quite that simple any more ! In general, the statement is correct, but there are a lot more details to it (more correctly, the alternator is not putting out sufficient voltage to satisfy the PCM; the PCM tells the dash to turn on the light).

Check ALL connections at the battery and the alternator for clean and tight.

On any light/medium duty vehicle built in the past 10-15 years, You should see more than 14.0V at the battery shortly after start up. If you drive for 10+ minutes and check the voltage, it will be closer to 13.2. THIS IS NORMAL OPERATION.

If the battery light is on a STAYS on after multiple re-starts and driving, then you DO need a new alternator.

12.5V on the battery after resting overnight and before starting is a little low. I think I would be more concerned about that !

[ksg5000]

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.

[SidecarFlip]

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.

[Sam_Spade]

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.

[wa8yxm]

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.

[fyrflie]

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

[Sam_Spade]

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

[Dale_Traveling]

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.

[ScottG]

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

[Johnny_G1]

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.