Charge Light

[djmiller109]

While driving my 99 Explorer the charge light came on. I had the battery tested, its good and I had the alternator tested its also good. I checked all my connectors to make sure they were tight also. The light is off now but what could possibly cause this?

 

[yavapaires]

While driving my 99 Explorer the charge light came on. I had the battery tested, its good and I had the alternator tested its also good. I checked all my connectors to make sure they were tight also. The light is off now but what could possibly cause this?

Low voltage, most likely. You can test tthis yourelf quite easily. Go to Radio Shack, WalMart, or, I recommend, Sears, and buy yourself an inexpensive volt,ohm,meter (VOM). With engine running, you should show around 13.6 volts at the battery cables. Engine off, about 12 volts minimum. To check the battery, with engine off, measure voltage. IE 12.5 v, turn on headlights for about ten minutes, measure voltage, if voltage drops noticeably, you have a weak battery. If battery is good, your voltage reading will be near what it was before turning on the head lights. If the voltage is NOT near 13.6 to 14 volts, with the engine running then the alternator is not putting out enough voltage. Most common reason is worn out brushes. For most people, it is easier to change the alternator, me, I would put in new brushes. But there can be other problems that I don't have tools to diagnose. Hope this helps.

 

[koda2000]

any time the "charge" light comes on it means that the alternator is not producing voltage to recharge the battery. this could be because of a faulty alternator or poor connection. when the "charge" light is on you are running off the battery. during daylight hours (assuming you don't use high amp accessories and your battery is good) you can drive a good ways on just the battery, but will eventually get too low to supply the ignition system and you'll be stuck. it should also be noted that a bad battery can kill an alternator because an alternator is designed to "alternate" between charging and not charging the battery as needed. if it has to run all the time to make up for a bad battery, the alternator will overheat and die.