Q: My 96 Ford Taurus alternator and battery tested good but battery won't stay charged

asked by on August 27, 2017

Car only runs if battery is fully charged for about 30 minutes. If u start the car then unhook the battery it doesn't run off the alternator it dies instantly. So of course every shop said oh replace your Alt which I did twice n still same thing. If you take the alternator off and test it it works fine as well as if you charge the battery it gets a full charge but if you test the alternator while on the car it reads nothing at all as if it's bad. I can't keep paying shops to change or test telling me it's a bad ALT when it's not that are the battery..Any Help on the subject?

My car has 144000 miles.
My car has an automatic transmission.

Battery will not hold a charge Inspection $94.99 - $114.99 Get a Quote

Hello. If the alternator is testing good then you probably have a failure in the control circuit for the alternator. This can be a fuse, wiring or it can be the computer. I usually need to test the circuit with a voltage meter to find out where the issue is. If you want to have this done, consider YourMechanic, as a certified mechanic can come to you to [see why the alternator is not charging] https://www.yourmechanic.com/services/battery-will-not-hold-a-charge-inspection

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing


Experienced Mechanic?

Earn up to $70/hr

What others are asking

Car not starting due to battery
If your vehicle does not crank, nothing operates electronically in the vehicle, then yes the battery might be dead. Depending on the age of the battery it might just be old and not holding a charge. If it is a...
Hesitation when accelerating.
You may have spark plug wires that are damaged or the plug you put in got damaged while putting it in the hole. If you accidentally closed the plug gap then the plug will cause a misfire. I recommend removing...
I'm looking for the heater blower fuse (30 amp)
The 1991 E250 Econoline does not use a fuse, but a blue fusible link wire that is off of the yellow wire, which comes off of the power side of the starter relay on the fender. This then goes straight...
Brakes not pumping up.
The best thing to do with a new master cylinder is to bench bleed it. Here's how: You use a vice to grab the nubs of the master cylinder and mount it up about waist high. If you don't have...
Can not get anti theft to turn off on my car
The first thing to do is remove the installed lock to see if the lock is seized or the latch is broken and needs replaced. If after the lock and latch is fixed then recheck the theft system to see...
Belt keeps slipping off
The possible causes of this include that the pulleys are not all in the same plane, the pulley on the harmonic balancer has shifted due to a break in the rubber bond, the belt tension is inadequate and/or the bearings...
I change the axle on my car and now when I put it into gear it does not go in gear and it makes a grinding sound
When a CV axle is removed some transmission fluid will leak out. The first thing to check is the transmission fluid level. If the fluid level is too low that will cause difficulty in shifting gears and possibly noise. Also,...
1995 Riviera 3800 Series II check engine light on and won't shift into O.D. at all but engine runs colder than usual.
If the engine does not reach operating temperature in a certain time the computer will go into open loop and may even lock out the overdrive if the problem continues. You will need to check engine codes to do pinpoint...
Car jerks makes noise and runs at a slow speed while driving
Check to see if the air filter and housing tubes are all hooked up and not cracked going to throttle body. Have the computer system codes checked to see what codes are stored and then have the codes pinpoint tested...

Related articles

2012 Chevrolet Malibu vs. 2012 Ford Fusion: Which One Should I Buy?
When you want a midsize sedan, you’re looking for something that will offer you the best fuel economy for the size as well as additional safety features that will keep your family safe while you’re driving across town or around...
How Long Does an Alternator Last?
Your alternator is a vital component in your car. It recharges your battery, using engine power, and it also delivers power to your...
Electric Cars and How They Work
Electric cars use an electric motor driven by a control unit. Their batteries are filled at charging stations and they produce no tailpipe emissions.