My battery light keeps coming on in my '92 Ford Taurus. The mechanic disconnected the battery cable to see if the alternator would quit and it didn't. What may be causing the battery light to come on and off?
2007-03-14 14:06:49 · 6 answers · asked by Nanc J 1 in Cars & Transportation ➔ Car Makes ➔ Ford
You may need to find another facility that can go into more detail. The alternator can still be causing the problem, and the waveform must be looked at. Also, has a load test for amperage output been done? Did they check the battery with a digital multimeter for excessive AC ripple? Was the battery subjected to a load test? A capacitance test? Is the field circuit to the alternator operating properly with a good duty cycle and output voltage? What is the voltage drop on the power and ground cables? Is there a short circuit to the light bulb for the instrument cluster light? If the battery is disconnected and the car is loaded (all accessories, lights, A/C, radio on), does it die then? These are all directions for the facility that does the work on it.
2007-03-14 14:18:31 · answer #1 · answered by Mtech 3 · 0⤊ 0⤋
I agree with M Tech but if I remember those things have a voltage regulator on the drivers side and it can cause issues including setting the battery light as it's thinking the alternator ain't charging (either not enough or what the regulator senses is wrong)
Pulling the battery cable on a 1980 and newer vehicle is a no-no as it can fry computers that way.. Bring it to another shop and let them actually test the system and see if it's a alternator, a regualtor or both (as later models, the regulator was built inside the alternator)
2007-03-14 14:23:53 · answer #2 · answered by gearbox 7 · 0⤊ 0⤋
ok lets start off by your mechanic did what? he disconnected the battery cable while the car was running....
one of the things that can happen from doing that is a big voltage spike in the system that can fry electroinc modules. The battery not only acts as a power source but a a large capister to obsorb those spike. find a new shop
now to awnser your question whats the voltage at the battery with the car running. whats the voltage at the black/ orange wire at the back of the alternator while its running? do they match?
you can also try this out your volt meter on a/c voltage and see how much a/c volt you have in the battery. if you see more then .3 volts ac then suspect a bad diode in the alternator.
you can also just take it off and carrie it your local pep boys or auto zone and they will bench test it no charge
2007-03-15 02:03:51 · answer #3 · answered by moe 4 · 0⤊ 1⤋
Hi Nancy,most likely culprit is the voltage regulator,internal fault.(just for your light)Have your charging system checked just to make sure your battery is charging.If so then your regulator is acting up.I seen this alot in the day I worked for ford.Good luck
2007-03-14 14:30:44 · answer #4 · answered by giff01 3 · 0⤊ 0⤋
Your battery could be bad, you might have a loose or dirty connection, your voltage regulator could be bad.
2007-03-14 14:10:43 · answer #5 · answered by Anonymous · 0⤊ 0⤋
Did the mech. turn on all accessories when he did his test? Have you added any optional equipment? ( speakers,amps, so forth) You may need a higher output altenator if so
2007-03-14 15:52:46 · answer #6 · answered by Anonymous · 0⤊ 0⤋