Finding a short?

[Mystic1]

What is the best way to find an electrical short. My battery is being drained to the point where it will not start the car after just one shift of work. This just started all of the sudden yesterday. I am thinking about pulling fuses one at a time and testing the circuts with a volt meter at the fuse. Will this work? I'm not that educated with electrical but it seems good to me. If the circut should have no power and it dose; theres your problem(at least this sounds good in theory)


Unitll I get it figured out I get to keep disconecting the battery when ever I'm not using the car :rolleyes:

[shepherd79]

first check the alternator. it may not be charging the battery. check the voltage on the battery when the engine is running.

[Mystic1]

Here are the vlt readings from the battery. I am sure the battery is good because if I disconnect it and let it sit over night at work, whatever it will start the car with no problem. And as you can see, the alternator is fine as well

Car off, Batt disconected 12.37V
Car off, Batt conected 11.25V
Car on, Batt connected 14.42V
Test was done when car was cold and all with in about 3 minutes time.

[pimp86LX]

what i do is find how much current is being drawn from the battery while the car is off. if its a slow electrical leak like i had it will be a small number but still significant. Then i start pulling fuses to see how if it changes...ones i find a circuit i try and find things that may be wrong. I found that one of my tail light builbs was corroded and had an electrical 'leak'

[Mystic1]

How would I go about finding out exactly how much of my power drop is the leak vs. how much is normal? Considering somethings requier a small amount of power all the time, ie: clock in the dash, sterio to rember settings exct.

[pimp86LX]

good question. I knew at one point...but that was a long while ago.

[Mystic1]

come on guys, someone has to know. Please help, having to disconect my battery in the pouring down rain is getting old.

[Gregg86DX]

I am experiencing the same problem and I took my car to one of those battery/alternator shops and they said the alternator was causing the problem. The alternator was charging fine, but a bad diode inside it was causing it to drain the battery when the car was off.

Gregg

[Mystic1]

Really? Never heard of that. But I'll give you 1 good guess where I'm going Monday morning. Thanks for the tip.

[wprocomp]

take a test light...disconnect your nrgitive battery cable...take the test light ground and put it on the cable and touch the neg post...it should be fairly dim...if its bright you have a prob...begin pulling fuses inside and out...it should eventually go dim when the right fuse is pulled...make sure and turn off your dome light to so it dosent make the test light bright...if that dosent work...try the starter and the alternator...good luck!

[Mystic1]

I don't have a test light at this time. Is there a way I could do this with a voltage tester. Like how many volts should there be in the ideal situation as well as the situation of a short. I am asuming that in the case of a short I would have almost/full power. Any way if you don't know; I will be picking up a light soon any way. Thanks for the tip.

[shepherd79]

go to autozone and they will hook up a mashine and it will test the alt. for you. it is free.

[Mystic1]

No autozone here but we have a Kragen that tests them. I can't rember if I have to take it out of the car to do it or not

[Gregg86DX]

No autozone here but we have a Kragen that tests them. I can't rember if I have to take it out of the car to do it or not

Look for places like "Start Mart", "Battery Exchange" or any place that specializes in Alternators and Starters. They should have a machine that tests "on-car" and only takes a few minutes.

Gregg

[Mystic1]

Well, I think I found the problem:

Fuse #4 under the hood, (Stop, Horn, Seatbelt retractors) (THANKS: WPROCOMP FOR THE HOW TO TIP)

Here is what I know so far (before it started raining). I have 1 brakelight bulb burned out. I pulled the bulb out and the connections where clean. I also checked the other bulbs and found no problem. This is as far as I have gotten.

Any one know the color of the wires going to the horn, and or how to remove the center cover of the steering wheel, I CAN TRY Well, I think I found the problem:

Fuse #4 under the hood, (Stop, Horn, Seatbelt retractors)

Here is what I know so far (before it started raining). I have 1 brakelight bulb burned out. I pulled the bulb out and the connections where clean. I also checked the other bulbs and found no problem. This is as far as I have gotten.

Any one know the color of the wires going to the horn, and or how to remove the center cover of the steering wheel. So I can try and isolate that part of the circut.

And what is a Seatbelt Retractor? A moter to retract the seatbelt when you take it off? I don't rember ever seeing anything like that. I have the door pannel off for other reasons.

[Mystic1]

Well, found the problem, it was the seat belt retractors. Not sure why or how bet they are the problem.. ..Thanks for all of the help

[wprocomp]

cool...yeah my headlight motor switch was draining my battery so I just took the fuse out and just manually move them...glad I could be of help=)

[smufguy]

go to autozone and they will hook up a mashine and it will test the alt. for you. it is free.

They dont Alex, i went to them when i had the problem of battery drain and they could not do it because it was pre-OBD or what not. Either way they said the altenator was fine because it was putting around 12.85 - 13.2 Volts. Thats all they can check, they cant check the starter or whatever that is included in their free electronic diagnosis.

[Mystic1]

[QUOTE=smufguy] they said the altenator was fine because it was putting around 12.85 - 13.2 Volts. QUOTE]

Sounds a little low for an alternator to me. Usualy their around 14-14.5

[smufguy]

not for the 3g altenator. The 3g altenator cannot put out more than 13 volts stock. Its the required.

[Vinny]

are you sure on that one????? I know Pauls manual states a 13.9-15.1 constant with headlights,blower motor, defroster ect turned on. I don't have my 88 shop manual on me but I'm pretty sure its the same

[Mystic1]

not for the 3g altenator. The 3g altenator cannot put out more than 13 volts stock. Its the required.

I'm not an expert but a good batery will hold 12.6 on avrage. I think 13 wouldn't keep the battery charged especally at night with the high beams heater sterio and what ever else you have going like fog lights and amps power windows. Not right a way but after a couple of hours constantly driving like this would drain the batery and cause electronics to fail.

[Gregg86DX]

When I had mine checked recently, it was putting out 14 volts at idle.

[smufguy]

I dont know which model (KA or KC) you looked at or the US or the European model. But anyway, i never bothered to look at the shop manual for the specs but thats what Mike (Egypt) told me.

Mine junkyard alternator puts out 13.5 volts on average. and yes, i do have heater, fogs running with headlights, amp and pwr windows. but everyday my car starts up at one crank. So i dont know why you say the battery would drain.