hatchbkdrvr

My car wont keep power. It just dies. So i drove up to the auto store and from my battery they said my alternator was bad and was only putting out less than 1 volt. But when i replaced my alternator with a new one the problem still consists. So i took my original alternator up to the auto store they checked it and told me it was good. The guy said maybe it was in the battery cables. But ive checked all those and they are fine. Another person told me it could be a bad fuel filter. That sometimes when a filter goes bad it can sometimes act like a bad alternator (I dont know how much I can believe this guy though.)

So anyways, suggestions are always appreciated because i have no where else to go from here. I have no idea why it is acting this way. I even bought a brand new battery and it just drained itself.

JDM Lyfestyle

Well it sounds to me like youve got a parasitic drain on the system that is simply draining the battery.

Have you recently installed any stereo equipment or anythin else electrical before the problem started?It could be simply something that is not turning off or worse something shorting out

hatchbkdrvr

I havent done anything new to the car electrical wise in over 3 months. This came out of no where. There are no shorts that I know of. The battery is just being drained its not recharging.

jdmztrane

Did you re-charge the battery after installing the new alternator? Sometimes when your battery is drained too low, it wont charge back to normal operating voltage because the alternator is not strong enough. Run it on a trickle charger until its fully charged and see if the problem persists. Then get back to us.

hatchbkdrvr

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jdmztrane &raquo;</TD></TR><TR><TD CLASS="quote">Did you re-charge the battery after installing the new alternator? Sometimes when your battery is drained too low, it wont charge back to normal operating voltage because the alternator is not strong enough. Run it on a trickle charger until its fully charged and see if the problem persists. Then get back to us. </TD></TR></TABLE>

The new alternator wasnt even necessary because when the problem still persisted even after i removed the old an installe the new one. So i took the original in to have it tested and thats when they told m it was still good.

hatchbkdrvr

nobody?

jdmztrane

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hatchbkdrvr &raquo;</TD></TR><TR><TD CLASS="quote">

The new alternator wasnt even necessary because when the problem still persisted even after i removed the old an installe the new one. So i took the original in to have it tested and thats when they told m it was still good.</TD></TR></TABLE>


You didn't understand what I was saying. You may have had a dying alternator. When you put the new one in, did you re-charge the battery? If the battery was drained past the charging abilities of the alternator, you would lose power. I had this problem once, thats why I said to make sure the battery is put on a trickle charger before you go and start it up.

So like I said.... go make sure the battery is charged using a trickle charger to make sure its fully charged. Then see if the problem persists. Then let us know your outcome.

fastrc2

ok, lets get tis straightened out. for an alternatot to work, it TAKES power in, from the battery, to energize the stator/rotor, depending on model. this field of energy crashes into the magnets field at right angles, which generates an A/C voltage, alternating current. this is rectified into direct [constant] current by diodes. these chop off the part of the sine wave that decides a/c or d/c. this is done within the voltage regulator. so now, this energy goes out of the alternator, through the thick cable to the battery. now, thats just the positive side, the ground side depends on the case's connection through its bolts, to the block and its bolt, and that depends on the blocks ground cables.

now, when checking electrical flow, this is current intense cables, so not only voltage you need, but amps, to test for amps, you need a test lamp, becuase a bad connection can still register 12 volts with a meter, but not light up a test light, so first, charge the battery all of the way slowly overnight with a slow charger. then start the car. measure the voltage at the battery. whatever it is, good or not, we want above 11.8 with a bad alternator, if it isnt the battery is very low still. hopefully you are measureing 12.5-12.7, anyhoo, test voltage measureing ground at the battery, to the positive big cables connection at the alternator. if it is the same or within 0.2-0.3 volts good first step, then take your test light from the same ground to the end of the cable, if it lights the cable, and ground should be good, now check the power in, the little wire which most people refer to as the idiot light, on many makes, is the power in to the alternator, do the same checks to the cable, this is a positive, and your looking for the same results as on the thick cable [ 12 volts when key is on]. if this doesnt check out, when you turn the key on, not start, but int he run position, when all of the lights on the cluster do a self test, does the battery light come on, and go off when you start it? if it doesnt come on at all, stop here. i have seen on fords where the bulb is in series to the little wire that powers the rotor of the alternator. [ 3 alternators put in one windstar] lol so now if everything is still good to the point, [ i assume the belt is good and tight] set the meter to a/c and attach from ground to the positive thick cable connection at the alternator, you should see less then 0.5 volts average, but up to 1 volt on a honda is ok. i also assume by this point all of the high rated fuses in the fuse panel are ok. i wish i typed it in earlier. if EVERYTHING checks out, then take the alternator, take it out, throw it through a wall, the store lied. its bad. now if they know how to bench test it in their shop, then by now you shouldve found out the problem.

i have seen that about 6 inches from the alternator, the thick cable passes through this bracket, and at idle, the voltage goes low becuase the cable has chafed through its insulation, check this for grounding. [intermittent grounding]

if you still cant find a problem, set the meter to ohm's and test the alternators case to the battery ground, you should have a very low reading, preferably 0.0 but up to 0.5 should be allright. check the thick cable from the battery positive to the connection at the alternator, same result as before.

if still a problem, reply, i am watching the replies to this post.

hatchbkdrvr

Thanks i appreciate the help......

But i still dont think you guys are understanding what im saying though. Or maybe yall are and im not understanding you guys.


Anyways i replaced my old alternator with a new one because i thought it was bad. I was getting all the symptoms of a bad alternator. My head lights would go dim then my rpm needle would bounce real crazily then my car died.
So I replaced my original alternator with a new one and the poblem still persisted. Not knowing what it could be i took my original/ old alternator to auto zone to have it tested and it passed the test two times when it was good.

So are you guys saying even though it passed the tests it still could be bad? Or now is it something in my wiring?

I will still try to buy a new battery or just try and fully charge the one i have now.
Ill let you know the verdict.

jdmztrane

I had a similar problem with my 98 DX Civic. The first time I just got a bad rebuilt alternator from a local auto store. Then the second one died and I couldn't figure out why. So when I went back to get a replacement under the warranty, the guy told me to make sure that my battery was fully charged.... not just a new battery. Turns out, with the new alternator and the fully charged battery, my problem was fixed. Your alternator wiring could be bad as well.... but a battery that is putting too much drain on the power the alternator is putting out can actually cause the alternator to go bad.

fastrc2

ok the battery you had before was bad, becuase they can act as a constant capacitor, and what i mean is that even though they crank the car over ok, they never stop taking in massive amounts of power, always charging, never peaking off on the input current, what this means is that the alternator was always working at maximum output. this will kill any old or new alternator, but on a new one, where the brushes are not seated in at all due to lack of being broken in, the surface of the brush gets too hot, burns and no longer conducts power, and then the new alternator has succombed to "alternator or starter death" there are warnings on some parts about this, this means cranking over a new starter on a low battery or a low battery starting a car with a new alternator, puts stress on it because of the batteries condition.

SO, yes indeed i am saying to the original person, you have an electrical issue. you already proved it by replaceing the alternator, and it never worked for even a minute. the conditions you stated that occurred right before the battery went dead, is the result of car electronics going "haywire" due to under voltage. they are not able to work correctly when source voltage goes below 10 volts at all, as the voltage drops int he first place, the 12 and 5 volt reference signals to all sensors drops too, and the sensors signal to the ECM is incorrect and the ECM is not even programmed to use low voltage signals, so things like fuel and timing go funny befroe it dies, and the speedo in you case was very jumpy, this is ok, just because of low voltage. so please check out the system as i have explained to find the problem.

hatchbkdrvr

So if the battery light never comes on in the cluster, then what?

fastrc2

does it illuminate when the key is turned to position 2, when all the other lights come on, but the car is not runnning?