[always wanted a pony]

Last year I replaced the alternator and the battery after confirming that the alternator was in fact bad.
Last week my car wouldn't start and after jumping it I had no power to the radio, the instrument cluster or anything else. I parked the car and killed the power, and it wouldn't turn back on until I jumped it. After I jumped it it ran and drove fine until today.
Today it barely started and the battery gauge was jumping around. I checked the battery and it was fine, but the alternator was at 12.7. I checked it again a few minutes ago and the alternator was back up to 13.7.....what gives? What should I check?

[Green_6er]

sounds like you got the wrong pulley on your alternator. where ever you got it from go tell them that they gave you a bad alternator and get a new one, and make sure that you take your old one aswell so you can compare them and make sure that you are getting the correct one. but i am only guessing that you got the wrong pulley on your alternator, compare it to ur old one and see if they are the same.

[RedDevilGT]

Was it a Duralast from Auto Zone?

[always wanted a pony]

it's from oriellys, remanufactured.

[Mr. Red Pony]

Voltage regulator is shot.

Meaning. Get a FoMoCo new Alt.

[goren813]

I'd always go new for alternators... Advance gives lifetime replacement on theirs. But I'd have it tested by Advance or elsewhere (free). And they'll tell you for certain.

[1slowv6]

dont get an alternator from a parts store like autozone, advance etc...

lifetime warranty or not how many times do you wanna replace the damn thing

get a NEW alternator not a reman and always go for one with more amperage output if possible. it wont hurt anything it can only help especially if your running a stereo system or anything of the sort.

it sounds like the alternator is bad and not charging the battery, remember the battery is only meant to START the car. not keep it running, if you were driving the car off the battery then that is why the radio etc wasnt working. and will also cause sulfation of the plates in the battery meaning its life has been reduced significantly.


BEFORE YOU DO ANYTHING check all connections and make sure they are tight

also feel your primary wire (aka battery cable) the wire that runs from the battery to the alt. if it is crunchy then u need a new cable.

you said you tested your battery and got a voltage reading?

if you have a volt meter or something then check for voltage drop in the wires becuase corrosion could cause the alternator to not be able to charge the battery when infact you have a perfectly fine alt.

[always wanted a pony]

how can i check for a voltage drop in the wires?

[1slowv6]

Originally Posted by always wanted a pony how can i check for a voltage drop in the wires?

put the leads of your voltmeter across the wires in parallel like. touch the positive of the battery to where it leads on the starter and disable your ignition. you get your reading while your cranking the car thats why u disable the ignition

the theory is that if there is too much resistance in the circuit the meter becomes "the path of least resistance" showing a voltage

an acceptable voltage would be .1 or less per wire

if you get good readings on that then at least u know ur cables are fine.

but like i said tighten all connections to be 100% certain that you dont have a loose connection in the circuit

if everything checks out and you continue to get a bad reading from the alternator then replace it

[goren813]

Advance sells new ones. With a lifetime replacement.

[always wanted a pony]

ok, thanks guys! I tightened down all the connections and it seems to be fine now, I guess time will tell.