Charging System Light

[dieselmatt]

Just today my charging system light came on. It will stay on at idle and during braking, but while moving it goes off. Any one have any idea what this may be or should I just take it in to Ford? Thanks

-Matt

[bigcountrysg]

Check the voltage output on the alternator.

[stroken04]

Originally Posted by bigcountrysg

Check the voltage output on the alternator.

I was thinking the same thing

[dieselmatt]

Well, I was thinking that too, but it doesn't really explain to me why the problem only occurs at idle or during braking. Any ideas on that part?

[Tacomarunner]

What should the output be?

Russell

[kinghawg98]

You probably have one dead battery. Disconnect both ENTIRELY, let it sit disconnected for a while (to get rid of surface charge)

Then test voltage on each battery. They should test about 12.6v

If when the truck is moving you have 13.6v out of the alternator, its probalby good.

[BLACKANDTAN]

if at an idle the alt. might not be putting out enough juice for the system, while running it might have just enough output to trick the system in to thinking it is enough. my alt. got weak and did the same thing, had to replace it. 2 month before i replaced both the orig. batteries. so i knew that there was only one thing that would cause it. the alt.

[korterman1]

Only a couple things it could be, batteries or the alt. Check battery discharge rate, this can be done @ most auto parts stores also @ the same time the alt. can be tested. If you are still under warranty ford should take care of the alt. Oh also check your battery terminals for corrosion and make sure the connections are tight.