Question about 2004 Ford Mustang

1 Answer

Battery light will not go off

Replaced battery, checked alternator (shows okay) has been like this for 6 months now. runs okay, battery light just stays on. battery charge indicator went to complete zero while driving this evening, interior lights went out, radio went out, ABS light came on... help, what's wrong with my car?? Had to jump it off to get in going again. Ford wants $200 just to hook it up to the machine to tell me whats wrong... I don't have that kinda money right now. HELP!!

Posted by on

Ad

1 Answer

  • Level 1:

    An expert who has achieved level 1.

  • Contributor
  • 2 Answers

I am posting a generic reply to the "charge fail" lamp (that is the correct term - when the lamp is lit = the battery is NOT being charged) problems rather than a specific cure for the ills in your car.

I suspect a faulty alternator OR an inadvertent short to battery - potential of the wire leading from the charge fail lamp to the battery charging alternator. Please try the following tests (BE CAREFUL while working - you are working near the engine + v belts + fans etc. and a fully charged battery = can be very dangerous)

Locate the three terminals of the battery charging alternator. The largest terminal would be connected to the battery positive cable (may be red in colour). The second terminal could be labeled as "W" = this is the terminal generating a frequency proportional to the engine speed for the tachometer. The third terminal is the WL or D terminal. The Charge Fail lamp is connected from battery positive (via the ignition switch) to this WL/D terminal.

Turn the ignition switch on but don't start the engine. Observe the "Charge Fail" lamp glowing in the dashboard. Now remove the wire going to the WL/D terminal. The "Charge Fail" lamp should now stop glowing. If the lamp continues to glow, there is surely a shortcircuit between the wire from the lamp to the alternator.

As this lamp current is not going to the WL/D terminal due to the short circuit, the battery charging alternator is not producing very little or no output. Check if the battery terminal voltage rises when the engine is running. If the alternator is working correctly, the battery would be at 13.2 Volts with the engine running.

The confirmatory test is to rig a spare lamp (12V, 3 or 5 watt lamp in a holder) between battery + to the WL/D terminal - if that works properly (lit when the engine is stopped and off when the engine ir running), you can connect a new wire from the lamp to the WL/D terminal - do isolate the earlier wire completely from from lamp as well as alternator end.
Hope this helps. Write back if I have confused you further.....

Apurva from Pune, India.

Posted on Mar 12, 2009

Ad

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya Mechanic can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repair professionals here in the US.
click here to Talk to a Mechanic (only for users in the US for now) and get all the help you need.
Goodluck!

Posted on Jan 02, 2017

Ad

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

How do i find what is draini g my battery? Battery is new (6 months) and if i turn car off and have any door, trunk open for longer than 1-2 min battery wont start car without jump


That only means, with your explanation, the battery is bad or has a dead cell. It happens. Have the battery fully charged at a battery rebuilder and have him load test the battery to find if indeed it is bad. If not, have your charging system checked. A test when running should show 14 volts or better, meaning the charging system is good. If the test shows the battery stays at 12 volts, it is not charging and your alternator is at fault.

Jul 10, 2017 | Cars & Trucks

1 Answer

2012 Grand Caravan. How do I turn the battery light off after installing a new battery?


Test the alternator. The battery light is for the charging system. Once the charging system is working with the engine running, the light should go off. If your light stays on with engine running, the alternator may need service or replacement.

To test the charging system, just put a voltmeter on the battery with engine running. The voltmeter should register at least 13.5 volts- alternator is charging. If you only show battery voltage with engine running, like 12.2-12.8 volts, the alternator or charging system is not working. The battery light should be on to signify this.

Jun 17, 2015 | 2012 Dodge Grand Caravan

1 Answer

Where is the alternator fuse on a 2001 hyundai sonata


The fuse is under the hood in the main fuse center

Jan 23, 2015 | 2001 Hyundai Sonata

1 Answer

Why does the battery light come back on after replacing both and alternator?


Have a auto electrician check that the 14.2 volts is actually dc current as it if it is ac then there is a problem in the rectifier of the alternator

Aug 26, 2014 | 2002 GMC Envoy

1 Answer

2002 Kia Rio the battery keeps dying while the car is running and the lights keep going down in the windshield wipers running real slow its got a six month old alternator the lights and turn signals go...


Charge the battery start the engine and confirm that the voltage at the battery is about 14 volts with engine running . If not it is likely the alternator is bad or the electrical connections from the alternator to the battery are defective.

A significant drain from the battery can be determined by observing the battery voltage after stopping the engine.

If it is under 12 and continues to drop trouble shoot for battery drain. If you suspect the radio pull the fuse and observe.

Jun 26, 2017 | Cars & Trucks

2 Answers

The battery keeps dying. the battery is 6 months new. what could be the problem?


make sure the battery terminals stay clean, once its fully charged, check the voltage on the posts with the motor running, you should read 14.5 volts ,, if not, make sure the connections are clean on the alternator,, check voltage again, if its not 14.5 volts,, your alternator is defective

Jul 13, 2011 | 2000 Dodge Grand Caravan

2 Answers

I was having problems getting my 1997 jetta to start in the mornings, after getting it jumped, it would be okay. I replaced the battery and was having no problems. On Christmas Day, I didn't start it at...


CHECK ALTERNATOR OUT PUT SHOULD BE 13.5 VOLTS TO 14.5 VOLTS.IF NOT ALTERNATOR IS NOT CHARGING BATTERY.CHECK ALTERNATOR FUSE AND CHECK ALTERNATOR POSITIVE FEED WIRE AND VOLTAGE REGULATOR WIRES.IF ALL IS GOOD ALTERNATOR NEED TESTING AND REPLACED.IF ALTERNATOR GOOD BATTERY CABLES COULD BE OLD CAUSING POOR GROUND AND HIGH RESISTANCE IN POSITIVE CIRCUIT. STARTER SOLENOID FAULTY IF NOT BEEN REPLACED.

Dec 28, 2010 | 1997 Volkswagen Jetta

2 Answers

Battery won't stay charged while running. Alternator is fine tho.


It seems that your battery is not getting its charging amount from the rectifier which comes from the dynamo when the engine is in running condition. So just your rectifier and check the output of the dynamo to be sure thats OK............sodeep

May 20, 2009 | 1994 Jeep Grand Cherokee

Not finding what you are looking for?
2004 Ford Mustang Logo

331 people viewed this question

Ask a Question

Usually answered in minutes!

Top Ford Experts

yadayada
yadayada

Level 3 Expert

77499 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22306 Answers

fordexpert

Level 3 Expert

5623 Answers

Are you a Ford Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...