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Old 07-15-2009, 02:50 PM   #1
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Unhappy Electrical Short

Hi, I have a 94 wrangler with a 2.5 liter. I had the battery replaced last fall and the jeep worked fine until about one month ago. After sitting idle for a month or so the battery went dead. I recharged the battery and cleaned the cables and posts. It started fine but was dead the next day. I can start the engine and remove the positive wire from the battery and it keeps running so I guess the alternator is fine. I checked the positive cable to the starter and it also seems fine however, the fuse box near the battery was indicating a short with my tester. I removed each fuse and rechecked the short and it never went away. What else can it be?

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Old 07-15-2009, 05:04 PM   #2
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what you are describing is a draw when it is constant. and yes you are correct that it can be called a short in the circuit if the short is from the battery to the consumer. Anywho, ide charge the battery a bit then disconnect battery and then reconnect in the morning and see if it starts. might just be a bad battery.
how did you check for a short/draw? not knowing your background in electrical i have to ask to make sure your testing correctly.

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Old 07-15-2009, 05:20 PM   #3
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probably just a crap battery depending what u have for cash i would go get the optima red top should last for a good long time and i'v never had a prob with one but that's just me
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Old 07-15-2009, 09:33 PM   #4
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I used a multimeter to check the current. If I start the jeep and remove the positive battery cable my alternator keeps the jeep running and delivers 14.8 volts, when I put the cable back on I can hear the alternator working harder. With the engine off I get a spark when I touch the positive cable to the positive battery post. You are coorect in your teminology when you say a draw...I just can't figure out where. Everything works fine if I remove the positive cable after I start the jeep.
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Old 07-15-2009, 09:37 PM   #5
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so how much of a draw is it pulling? .030A is about max
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Old 07-16-2009, 05:45 AM   #6
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It is drawing 11.8V thats why it seems like a dead short. If I run my meter between the positive and ground it also reads 11.8V.
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Old 07-16-2009, 06:22 AM   #7
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It is drawing 11.8V thats why it seems like a dead short. If I run my meter between the positive and ground it also reads 11.8V.
Ok,i see now. You are doing a voltage test and not a draw test. 11.8v at battery + and - is an insufficiently charged battery or a battery that cant hold a charge.

a draw test requires disconnecting battery and putting meter inline while in amps mode.
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Old 07-16-2009, 06:58 AM   #8
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As it stands, I leave the positive battery cable off and place it on only to start the jeep. It starts fine, then I pull the cable off because of the constant drain on the system when it is connected. My dash guage jumps up from around 11 to 15 when I disconnect the positive lead. Again I can hear the difference in the way the alternator sounds.
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Old 07-16-2009, 07:14 AM   #9
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I tried a draw test as you described. I connected the positive cable back to the battery ( it was disconnected all night), started the jeep, removed the positive cable and placed the red lead from the meter to the battery terminal and the black lead to the positive cable. In DC Amps mode nothing happens, in OHMS mode it reads .30. With the meter in DC Volts mode it reads -3.9.
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Old 07-16-2009, 07:41 AM   #10
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I just pulled both the positive and negative battery cables off and checked for DC volts across the positive battery post and the negative cable (disconnected), I measured only 7.70 Volts. Across the battery itself I got 11.7 volts.
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Old 07-16-2009, 05:30 PM   #11
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I tried a draw test as you described. I connected the positive cable back to the battery ( it was disconnected all night), started the jeep, removed the positive cable and placed the red lead from the meter to the battery terminal and the black lead to the positive cable. In DC Amps mode nothing happens, in OHMS mode it reads .30. With the meter in DC Volts mode it reads -3.9.
wait, you need to stop and ask questions. why would you do a draw test if its running? Your problem is when its not running. you probably blew the fuse in your meter which is likely rated at 10amps and your alternator passed about 90 amps through it.

check fuse if it has one and replace if needed. then redo test while engine is not running. Another point is not to run engine with battery disconnected or you will be replacing alternator soon.
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Old 07-17-2009, 11:56 AM   #12
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With the engine off I placed the multimeter in line between the positive battery post and the positive cable. The draw is .058.
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Old 07-17-2009, 12:09 PM   #13
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my guess is the battery they can do some strange things. i had a similar issue with mine not long ago. when i charged and cranked it the alternator would scream to the point i thought it was going to lock up. when i took the hot post off it would idle back to normal and the alternator would quit sqealing. new battery fixed it all.
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Old 07-17-2009, 01:36 PM   #14
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The battery is new, starts the jeep and stays charged as long as it is disconnected. I guess I could return the battery because it is pretty new.
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Old 07-17-2009, 06:41 PM   #15
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having a draw of .058 is kinda high especially since jeeps dont have many electronics. while hooked up in amps mode remove one fuse at a time til reading open. your at the range of draw for memory of electronics like radio, lcd clock, and such. stuck relays are normally .10-.30 amps a peanut bulb is about .08 amps. you mentioned looking at all that before but did you also try disconnecting alternator? alternator has 3 diodes built in to prevent battery voltage going back into alternator. when one or more diodes goes bad battery voltage runs through alternator windings and makes it a heater.
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Old 07-18-2009, 10:28 AM   #16
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I have this feeling that the problem is in the fusebox next to the battery. I disconnected the alternator and still had the short at the battery post,so I reconnected the alternator. I removed all the fuses from the box under the hood and the short disappeared. I reconnected the battery. I then checked for voltage from the positive side of the fuse blocks to the negative side of the battery, they all checked out (11.8V). I checked for draw across all fuse terminals and found nothing, I turned on the headlights and checked for draw across the corresponding fuse terminal and it read .013 I also checked across the other terminals with the headlight switch still on and found a draw of .006 across the 50 AMP FUSE BLOCK terminals, all others were .000.
I then disconnected the positive battery cable again and checked for volts from the positive post to the positive cable. With no fuses I get about .75 volts. With the 30 amp fuel fuse re-inserted I get 11.62 volts. I then removed the fuse and checked volts with only one fuse in at a time. 50 amp ALT PWR 1.32V, 50 Amp FUSE BLOCK .89V, 40AMP IGN. 10.92V, 20 AMP HAZARD .76V, 50AMP ALT PWR1 .99V, 30 AMP HEADLIGHTS .72V, 20AMP HORN FEED 11V.
This is a frustrating problem.
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Old 07-18-2009, 05:51 PM   #17
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Ok, so you removed the fuses and the draw went away. The thing to concentrate on is which single fuse removed the draw. Find out which fuse and what circuit it powers and then look at that circuit. Do the draw test again but remove one fuse at a time till draw goes away. dont over think your situation. you have a slight draw so just pinpoint that.


dont look at voltage, look at current.
current(amps) is the measure of how much electricity is being cunsumed. voltage is 12v and that is constant. when something requires 10amps its using less than something needing 50amps but both get 12volts.
know what i mean? not trying to confuse so if i am just tell me.
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Old 07-19-2009, 09:42 AM   #18
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No you are not confusing me. Thank you for the clarification, I appreciate the help you are giving me.
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Old 08-02-2009, 09:09 AM   #19
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I have been on vacation but am back at the jeep problem. I think I have it narrowed down to the steering column. I am measuring .020A draw across the Ignition block fuse terminals under the hood and .040A draw across the horn terminals under the hood. If I pull the ignition fuse under the dash board I still measure the same draw at the ignition terminals under the hood. I pulled the wires from the horn under the hood and that changed nothing. Should I remove the steering wheel and if so how?
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Old 08-02-2009, 11:03 AM   #20
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There are also 2 very small fuses in the fuse block under the hood. one is 10amp and the other 15amp. if I remove the 15 amp the .040A horn draw disappears but the .020 ignition draw remains.
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Old 08-07-2009, 05:37 PM   #21
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next step since you narrowed it down is which consumer is getting power. disconnect consumers while testing draw at battery. first unplug igntion switch, should drop all draw, if not then you can likely rule out steering and other switched controls such as wiper motor and ecm. what i would do is start unplugging consumers one by one. dont forget relays as they also consume, especially hazard relay which is always powered. makes sure to unplug under dash switch in door so you arent looking at that draw. keep the meter on draw only.

just start unplugging things til draw goes away.
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Old 08-10-2009, 03:47 PM   #22
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I unplugged every consumer I could find starting with the fuses under the dash. Pulled & checked for draw one at a time, no change. Then I unplugged every wire harness I could find. Unplugged & checked for draw, no change. I have a .001 draw at the 20A HORN fuse in the block under the hood next to the battery and a .002A draw across the 40A IGN fuse also under the hood. When I check the draw from the positive battery post to the cable with all fuses in it reads .002. I can't believe this crap. I wonder if it could be in the fuse block.
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Old 08-10-2009, 04:38 PM   #23
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.002 draw is good. even .020 draw is good. once you go above .035 milliamps you should start worrying. your original draw was .058 so it sound like whatever you did removed the draw.
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Old 08-12-2009, 05:42 AM   #24
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I have noticed the amount of draw decreased. Won't ..020 kill my battery?
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Old 08-12-2009, 05:39 PM   #25
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I have noticed the amount of draw decreased. Won't ..020 kill my battery?
No. .020 amps is really nothing for a good battery and should be ok for several weeks.
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Old 08-14-2009, 05:28 AM   #26
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Thank You, for all the help.

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