The Ford Windstar battery light stays on and the battery still runs down after installing a new battery and alternator - what to look for and test?

Answer 1

I have a 96 Windstar & had some charging problems as well. I narrowed mine down to a series of faulty NEW alternator/voltage regulators (Good thing they are on warranty).

Don't assume a replacement part is in serviceable condition. One winter I went through 6 rebuilt starters.

AnswerI've owned a lot of older cars and run into similar problems on vehicles.

Try this: First ensure your battery terminals are clean and free of corrosion. Make sure you use a battery tool to clean them up to ensure a good connection. reconnect and tighten.

NOTE: Some electrical systems need to have the system computer reset after changing an alternator. If you changed the battery first, then changed the alternator, this may not have happened. Sometimes it's as easy as fully disconnecting both terminals and reconnecting the battery.

Check the voltage from the positive terminal of the battery to the negative terminal on the battery(record this).

Then check voltage from the positive terminal of the battery to where the negative terminal connects to the block. if this reading is lower your negative battery cable may be the problem. I've had them crystallize before from age so badly that they lost flexibility and began breaking internally. Replace it.

Then check voltage from the smaller positive cable post on the alternator and the negative terminal on the battery. If this is lower the smaller cable may be the problem. Replace it.

Then check voltage from where your positive cable hooks up to the solenoid and to the negative terminal on the battery. if this is lower your positive battery cable may be the problem. Replace it.

Charge the battery fully and take the vehicle to a local auto parts store and see if they can run a charging system test (usually a free service). They should be able to tell you what kind of shape your battery is in and the alternator output. A good alternator will put out 14+ volts, if it's putting out 12-14 volts it's wearing out and needs replaced.

If your alternator is putting out 10-10.5 volts or less means one of the diode pairs are bad, 5-5.25 volts or less 2 diode pairs are bad. Either way the alternator is not charging the battery and it's the fault of the voltage regulator.

Ask the person doing the test if he can tell you what the field voltage is on the alternator. If they can and it is around 12 volts or more you can probably bypass the next test.

Start the vehicle and hold a steel tool near the back of the alternator (not on the pulley side). It should be drawn magnetically to the center of the alternator. If it doesn't your alternator is not generating the magnetic field needed, to generate electricity. This could be due to a bad alternator or wiring.

WARNING: The next test is the "old fashioned" way we shade-tree mechanics used to do this. It can be done with the engine running in most cases, but you must be extremely careful that you don't get clothing or long hair anywhere near the pulleys. You do this at your own risk. If you are uncomfortable with taking such a risk, have your mechanic look into it. Disconnect the two wire box-like electrical connector from the alternator's voltage regulator and see if there is any voltage (should be around 12 or more volts DC) from the wires going to the alternator. You can try testing this with the engine shut down and the key on, but it may not work on all vehicles. -

With connector disconnected, if the voltage is less than 12volts or non-existent, it's a wiring problem. - With connector disconnected, if it is 12 volts or above it's probably the alternator (Bad windings.)

Set the multimeter to Ohms. Touch probes together and calibrate the needle to zero on right side of meter readout. (If the needle does not move to the right, you may need to replace the meter's battery or fuse). With the Alternator connector disconnected check the resistance of the alternator at the connector blades. If the needle goes to infinity, there is an open circuit in the windings. Replace the alternator.

Other things that can cause charging system problems:

• Excessive starter draw - Remove starter and take to parts store for testing
• Bad solenoid
• Failed engine compartment fuses or resisters - Look for and check big rectangular ceramic ones as well on antique/classic vehicles
• Failed fusible links
• Failing ignition switch - Usually under the dash, Not at the key
• Wiring to the key assembly inside the steering column - or on the dash older vehicles
• Bad computer modules
• Electrical wiring - This one takes the longest to isolate
• Particularly hot wires arcing to ground
• Some other Windstar threads suggest checking wiring bundles under the rubber boots at door hinges.
• Other unassociated electrical components shorting to ground and placing a drain on the system - could be anything from a cigarette lighter, to lighting, to electric radiator fans failing to shut off, ignition coil, radio, sensor probes shorting to ground, etc. etc.

AnswerThe yellow wire in your Alternator plug Have a "Fuse Link" at the starter relay. If that fuse link is bad the alternator will not charge. To test jump the yellow wire with the hot wire at the alternator and if the alternator is new it should charge. Check and install the fuse links. AnswerAnother thing to check is the battery. If the battery is going bad then it can accept charge to a certain point, but not enough to run the starter motor. That sort of thing. I always change the battery whenever the alternator was the problem. It usually fries the battery too. AnswerMany auto parts stores offer free battery and alternator testing - both on and off the vehicle. I would heartily recommend having them tested before buying the new one.

a "non-technical" way to check the alternator is to wait until it's dark then start your vehicle and turn on the headlights.... if the alternator isn't working the lights will be dim and soon the engine will quit running as the battery will have no charge left to provide spark to the spark plugs... if the alternator is only partially working the lights will stay dim and some of the electrical equipment may not work properly. The battery will require frequent "jump starts'. The battery may be running down because of a short out in the starter or some other electrical appliance.

Alternators do not have to be removed from the vehicle to be tested. Many shops and auto parts stores have diagnostic equipment that will thoroughly test the alternator - and many times will offer the service for free.

AnswerIt appears that your alternator is charging just not that well. A fool-proof sure-fire way to check if your alternator is charging is to start the car. connect dvm to battery pos and neg terms. Turn everything in the car on. Radio, lights on high stuff like that. The voltage should not drop much below 13 volts. It should hold steady around the 13 volt mark. It should actually be in the 13 area but not more then 15.5 volts if I remember right. If it is not charging fast enough then your lights will get dimmer and dimmer. Hope this helps.

Many auto parts stores offer free, on-car charging system testing.

there should be a light or gauge in the dash to indicate charging of the alternator. If you have to jump start it and the gauge doesn't hit 13 or so, your alt is probably bad. You can try this, jump start it, take the battery cable off while it's running. If it dies, the alt isn't charging. The best way is to use a voltage meter and measure dc volts at the battery. With it running, 13 or more. less than that and the alt is bad.

Answermake sure the glove box light isn't staying on AnswerThere is something drawing down the battery - and a common problem is the door ajar sensors causing the interior lights to stay on.

See "Related Questions" below for more about that.

three things, either your battery needs to be replace especially if it's around 5 year old, you have a lose battery connection, or you have a defective alternator...if you could check all of these things or if you could take the battery to autozone or advance auto parts they could check that for you at no charge...

Your alternator is shot.

I had a similar problem with my windstar. after replacing the alternator, I continued to have problems with my battery draining so I bought a quick-charger/voltage tester. After lots of troubleshooting I determined that the serpentine belt needed to be replaced and have not had any problems since. Check your serpentine belt, if there is any sign of the belt having wear such as a glazed look, replace the belt. I thought mine was fine, all it had was some minor glaze that looked like little specs of glass in the grooves of the belt. I replaced it anyway and my problems stopped.