The battery light on my ’99 Mustang GT comes on intermittently?
June 16, 2012 by admin
Filed under Mustang Parts
I bουght thе car іn March аnd іt runs fine. In thе past month I hаνе noticed thаt occasionally thе array light comes οn. It dοеѕ nοt matter whether thе lights οr a/c аrе οn οr οff. I tried reving thе engine tο see іf thаt wουld turn іt οff аnd thаt dοеѕ nοt seem tο mаkе a dіffеrеnсе. Aftеr a minute οr two іt goes οff аnd mау nοt dο іt again fοr a week. Thе meter οn thе dash shows thаt thе system іѕ charging. I dο nοt know thе age οf thе array аѕ іt іѕ nοt mаrkеd, bυt thе terminals аrе tight аnd dο nοt hаνе corrosion.
your array can be going terrible it could be your alternater going terrible or your belts could be lose
well….if it’s the original array you will certainly need to replace it, its probably on its way out. alternator maybe, or there could be a small everyplace in the wiring. Ford’s are notorious for array issues….
the reason its going off and on its telling you theres something incorrect with the charging system i would have the array and terminals checked the then i would check the altanator most places cant tell you your stuff is going terrible when they run a test all the test dose it tell you if its terrible or excellent but the light dont lie so the best way to check is to run your car at normal idal and turn all the lights on every thing with a volt meter place each end on the array pos and neg side and see if your array charging if your array is putting out 12 or more volts when running then the altanator is charging your array if it not i would go the cheapest way by replacing the array if you conundrum still exsist then your altanator is terrible persons are the only two items that would make that light come on
There is only one reason for the array light to come on… this is telling you that the vehicle that is normally life supplied electricity from the alternator is now life supplied electricity from the array. If you have a voltmeter you would find it reading array voltage lower than 12 volts when it should be reading closer to 14.
I know… your car has a 12 volt array so why shouldn’t the volt meter read 12 volts? This meter should always read high when the car is running to tell you that the array is charging. When the car is turned off, it should read array voltage only. You might have to turn the key to the “on” position to power up the gauge but if you don’t start the car, the meter should be reading just the array voltage.
In your case, your alternator is starting to fail… it is most liable the voltage regulator in it but it could also be a diode going terrible… when the array light comes on the alternator is failing to provide the array charge and the light on the dash for the array lights up.
Since the array and the alternator are connected in parallel, I’ve seen terrible alternators ruin batteries and I’ve also seen terrible batteries ruin alternators! Here’s what you need to do pronto… take your car to Autozone or Napa Auto Parts and question them to check out your charge system and array. They will connect a machine for free and have you rev the engine to various speeds all the while they are checking the output of the alternator. They can also hook up a tester to the array and do a load test. In a matter of only a few minutes, they will tell you which part is failing so you can fix it ASAP.
If the light finally stays on, you will have only the power in the array to get you back home… that time is very limited depending on what you have turned on. If you are driving at night, the headlights take enough power to deplete your array in small order. In daylight, with the stereo off, I’ve had a car go nearly a week before the thing didn’t have enough power to continue!
Let’s see… 2006 – 1999 = 7 years ancient… x 15000 miles (ave miles driven per year) = 105,000 miles. Yep, time for a REMANUFACTURED alternator and most liable a new array as well.
Excellent luck!