2004 Ford Mustang Logo
Posted on Mar 12, 2009

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!!

1 Answer

Anonymous

Level 1:

An expert who has achieved level 1.

  • Contributor 2 Answers
  • Posted on Mar 12, 2009
Anonymous
Contributor
Level 1:

An expert who has achieved level 1.

Joined: Mar 12, 2009
Answers
2
Questions
0
Helped
1940
Points
5

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.

Add Your Answer

×

Uploading: 0%

my-video-file.mp4

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

×

Loading...
Loading...

Related Questions:

0helpful
1answer

Where is the alternator fuse on a 2001 hyundai sonata

The fuse is under the hood in the main fuse center
0helpful
1answer

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.
0helpful
1answer

Replace battery and alternator 2x in 6 months

Get a cheap multimeter and test for drain, sometimes it is the starter, check the battery at all off, and running, your parts I hope are warrantied have them both tested and checked, The starter and or coil can cause weird electrical issues and a bad ground could be causing everything to work harder. You need an honest mechanic who cares about solving the problems.
0helpful
2answers

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.
2helpful
1answer

Battery will not keep power to start,especially overnight, have to jump battery often. How would i know if problem is battery/alternator/ connection?

Well, you start with the battery. It needs to be FULLY charged, that means about 4 to 6 hours on a real charger. Then you load test the battery.
If battery checks out okay, pull the alternator and have it bench tested, specifically test the diodes for open.

To narrow down the offending system/item: pull interior light fuse, and clock fuse, disconnect negative battery terminal, and put a light between the cable and the battery terminal (or a volt meter). if the light lights or you show voltage, disconnect circuits, one at a time, and retest....Eventually you will find the offending item.
1helpful
2answers

1985 dodge powerwagon, lights went dim driving home now wont start, just replaced battery 6 months ago. starter clicked at first then nothing.

The alternator may not be charging the battery. Jump start it, and use a volt meter at the battery, red lead to positive and black to neg. The meter should read between 13 and almost 15 volts, any lower than 13 volts, the alternator is no good. (this is done with vehicle running).
0helpful
1answer

Starting Problem

Probably a bad starter as well. A good battery can make a marginal starter work, but over time the battery will be weakened by the drain of the starter or the starter will get worse.

Remove the starter and take it to your local parts store for testing and replacement. Bring your battery along as the bad starter might have toasted it.

Also a bad battery can wear out a starter quickly.

We had issues like this with our pickup truck a few years back. Replaced the battery, worked okay for a while, then the replaced the starter, worked okay for a while, then the battery was bad. Eventually replaced both and haven't had any issues since.

So when replacing one it is a good idea to check the other.
0helpful
2answers

1990 buick no start turn key dash lights go out and all is dead

When you say "turn key dash lights go out and all is dead", do the lights come back on when you turn the key back to "off"?
With key off, try turning on your headlights- are they bright?
Flip to high beams-do they get brighter?
**If lights get dim while trying this, it's the battery-(dead/needs charged or replaced-which may have been caused by a bad alternator).
Leave lights on, now turn your ignition switch to "on"-do the lights get dim or go out?
Try and start the car-anything change?
If the lights were fine until you tried to start the car, more than likely your battery terminals need cleaning/tightening.
The lights should at least get dim when you try and start the car but only while the starter turns over: when the engine is running your lights (as well as all your other electrics) are powered by the alternator.
If you do all this and lights are okay all through this procedure, your problem is probably in your starter circuit. (Starter relay, ignition/key switch)

Hope this helps.
10helpful
2answers

Battery light comes on and goes off

CHECK ALL WIRES THAT GO TO ALTERNATOR.CHECK BATTERY BY TESTER( LOAD).CHECK WIRES FROM IGNITION SWITCH (YELOW) WITCH GO TO ALTERNATOR.AND CHECK GREEN RED WIRE WHITCH GO TO ALTERNATOR WITH IGNITION ON. IT SHOUD BE 12V AND WITH ENGINE RUNNING IT SHOUD SHOWS NOTHING.IF EVERY THINK OK - REPLACED ALTERNATOR.WITH EVERY THING OK VOLTAGE SUPOUS TO BE 13.8 - 14.5 V
Not finding what you are looking for?

397 views

Ask a Question

Usually answered in minutes!

Top Ford Experts

ZJ Limited
ZJ Limited

Level 3 Expert

17989 Answers

Thomas Perkins
Thomas Perkins

Level 3 Expert

15088 Answers

xxxxxx xxx

Level 3 Expert

5117 Answers

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

Answer questions

Manuals & User Guides

Loading...