small short killing battery

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glhx

glhx

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we traced the short to the main alternator wire. can an alternator cause a short internally when the car is off?
 
yeah i have a volt meter. test power at the starter relay. when the engine is off is shouldnt be drawing any amps?
 
if no multimeter handy a crude method...........remove battery lead from battery, tap it on terminal post momentarally making/breaking contact., there should be NO sparking..........wont tell you current draw but will suggect a problem......amps flows inline, voltmeter accross circuit, your multimeter should have a 10a max inbuilt setting, pull the plug leads out of multi and place in appropriate holes,dial multi to Amp setting,disconnect positive battery terminal place one end of lead on battery post and other on battery lead, HINT get your settings right on multi and make sure your leads ore in correct holes, you are effectivley making a SHORT CIRCUIT here and you dont want to fry your equipment or hands!
 
doing the crude method. i am getting a very tiny spark. it is inconsistent. this was how i traced it to the alternator wire. with the engine off there should be no current draw, i will test between the lead and the post and see what i get
 
i switched the volt meter leads to 10A. then set the meter to 10a on the dial. the display went to 1 and i got no reading on anything at all......



i still have the short. i still do the crude test by seeing spark at the battery. so far....i thought it was the alternator because it stopped sparking. I found out today it is not the alternator. with the main wire disconnected it still sparks.

i pulled all the fuses.....unhooked the alternator main and field wires.....unhooked the small solenoid wires on the starter relay, unhooked the main starter wire, balast resistor, coil.

What else is there? note i did all these removing of components separate. not everything was removed at once. Still, whats left?
 
If you have a stereo that has a memory in it (clock/radio stations/CD memory) there will be a wire connected directly to battery power as well as a "keyed" power source.
You could have more than one draw, leave the alternator wires disconnected while checking.
 
there is no radio in the car. i have unhooked everything i can think of. it drains the battery from full charge in 2 days.
 
You're probably pulling current (measured in Amps or Milliamps) from you battery which should be easy to find using any ammeter in series with the battery positive post. My first guess is a light being left on somewhere. Check at night for a glove box light or something else still on.
 
I'ts possible that you have a bad diode in the alternator. Do you have another alternator that you could put on it?
 
See what happens if you disconnect a bulkhead connector. You might be able figure out if it is under hood, under dash or chassis.

Check for added equipment wiring under dash. Auto alarm, or tach improperly installed.
 
I've had an issue with the voltage regulator in the instrument cluster.. you might check there, it acts like a bad alternator.
 
ill check all of this. i did just install a tachometer. and tied in the light to my shifter to the head lights. it was only then that i had this problem. nothing is left on, i thought it was the alternator so i replaced it. still has the power draw.
 
could it be a bad battery. i had it tested and it showed a negative. i bought a new one
 
glhx said:
could it be a bad battery. i had it tested and it showed a negative. i bought a new one
Click to expand...

Batteries can short out internally yes. Could it be the battery, I doubt it as you said it will light a test light with the battery cable disconnected

You need to start from the beginning if there is still a draw. Disconnect everything including the alternator and all fuses, see if there is a draw and then start putting in fuses one at a time to see if the light will light.
 
dont know yet if it is still shorting. the new battery is making the alternator not work as hard. the volt gauge used to fluctuate from 12 to 14 at all times and make the headlights flicker. it now stays at 13 constant
 
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