Put a new altanator on the car and it keep showing on and off

must be a bad wire if you put a new battery and alternator in it. Are you sure the battery and alternator are good. One way to test the alternator is to run the engine and disconnect the battery [one post] while the car is running. If the car keeps running, the alternator is good. If engine cuts out and shuts off, alternator is bad

Your alternator is not putting out a regulated output, this is most likely due to a faulty diode pack, your cheapest option would be to locate a second hand alternator or maybe price a new one? the part can be replaced but can be a pain to remove and can require some specialist tools.

if the battery was disconnected , the computer might need to be reprogrammed from a authorized mechanic ..This process take 8 to 16 hours... BMW changed my battery in my 545i & didn't program my computer. The transmission was shifting wrong & they said I needed a new transmission ... I took it to a different mechanic & found out the computer needed to be programed .

A fresh charged battery does not mean it is a good battery.The battery is working the alternator to death,replace it,it has a bad cell,or the amps are to low,and has a short in it.The alternator senses the battery is in bad need off charge,and puts all out until the alternator has nothing left,This is the most likely cause of this problem.Also be sure the battery cable ends are shiny clean when replacing the battery.

if the battery light won't go of after replacing the battery you have a bigger issue, chances are the altanator is not putting out enough voltage. I would have that check as soon as possible, that way you don't die on the road. when the car is running the altanator should be putting out 14.6 volts at all times, if it is below 13 then the altanator should be replaced.

altanator needs to be checked may need replacement

Did you ever figure this problem out? I am having the same issue! i bought a new battery, new alternator, but my jeep keeps dying! i did the battery draw test, as soon as i pulled the fuse block battery feed out the draw was completely gone. can you please tell me what you did, this has been driving me crazy for over a month!

all you in fo is not there if you said your battery was dead but you could jump it and it would run but not charge battery then you altanator is working but you have a dead seal in the battery replace battery and you will be fine but if you drive it to much with bad battery your altanator will go bad from over working

Alternators require a + feed from the battery before they start charging. Make sure 12v is reaching it from the switched live supply.

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i am haveing the same problem... i have removed all the fusses the car doesnt need to start .. ive put 4 new batteries and an altenator in the car.. and it wont hold a charge .. i disconnect the battery at night and thats the only way the battery will hold a charge..