Electic Leech!

[702_MJ]

Ok well try to turn on the truck after sittn for a week. And it doesnt have enough juice. So theres gotta be something taking charge away from the battery when it sits. Any ideas where to start?

 

here's whats been done, the battery is about 4 months old, but was dead on arival to hawaii. And now its dead. I noticed it always seemed a little under 12 volts on the volt guage in the morning sometimes. I also replaced the alternator 4 months back. The other battery was dead and i did that little light test if you hook the negative up to alternator wire and the light turns on the alternators bad or something. Any way went back to autozone and tried to exchange it(life time warranty on a re manufactured alternator) they gave me some song and dance that the voltage regulator is bad on my truck. LOL the voltage regulator is in the alt. what morons. But thats all ive done.

 

I plan to buy replacement battery cables from jeepersandcreepers, or just make my own. Anyone got any ideas where this power sucker could be?

[DirtyComanche]

Lots of junk can do it... I can't think of anything off the top of my head that is 'typical'.

 

The quick way to start eliminating things is to get an amp clamp, or run an ammeter inline with the positive cable (NOT a fan of this) and then start pulling fuses, one by one, and see if the amperage drops when you pull one in praticular. Then you at least have a starting point for what circuit is the culprit.

 

And if there's any hack wiring on the truck, I always suspect that. You know, that wiring that some PO did trying to 'fix' something or install a stereo or whatever. My chevy has more hack wiring than proper wiring - it took me about a half hour to figure out how it was actually capable of starting and running.

[702_MJ]

Hmm process of elimination it is then.

[mfpdm]

I had a power drain on the 86. Battery was about three weeks old. Jumped it and charged it back up. Next morning it was dead. Went to pull the paperwork for the battery out of the glovebox and found the problem. The glovebox door was not latching all the way so the light would stay on. :doh:

Adjusted the latch and fixed the problem.

I will have to say though, the battery lasted three weeks with the light on which kind of impressed me.

 

:cheers:

[702_MJ]

hmm that could be, my bracket is broken. I was gonna go grab it from my bosses cherokee that he is scrapping but in hawaii it rains ALOT! so far 1 week straight :fs1: Any way I also just hooked my fan up to a switch and the switch goes to the fuse box in the BATT terminal. Maybe it could that, but i kinda doubt it cuz its hooked to a relay.

[702_MJ]

Ok so disconnected the glove box light. Jumped the truck and let it run for about 15 mins. Came back about an hour later and it got drained just enough to make me angry.

 

Any one know where i can buy a good multimeter for a decent price?

[jtdesigns]

Goto Lowes and get you an Ideal.. Best bang for the buck.

[mfpdm]

I forgot one part of my story. The reason the battery was a few weeks old was that my other one, which was probably about 7 months old would not hold a charge very long. Got it from advanced auto. I had my son just for sanity sake, take it back to them and have them test it. Ended up having a bad cell and they replaced it under warranty. Guy said it just happens sometimes. Reason I bring that up, is have you had the battery tested even though it is only 4 months old? Just a thought.

 

:cheers:

[702_MJ]

LOL theres no lowes here on the island. Home Depot should work :D

 

I havent had it tested YET. I was gonna check if the water level was good too. Running blind trying a process of elimination

 

Course while she is down i got time to do things i havent had time to do course it would stop raining :fs1:

 

hawaii aint that tropical at 4000ft elevation!

[TNT]

LOL theres no lowes here on the island. Home Depot should work :D

 

I havent had it tested YET. I was gonna check if the water level was good too. Running blind trying a process of elimination

 

Course while she is down i got time to do things i havent had time to do course it would stop raining :fs1:

 

hawaii aint that tropical at 4000ft elevation!

 

A test light will work also. I have chased voltage draws a ton of times.

 

Remove the keys from the ignitions and close both doors.

 

Disconnect the battery positive battery termal and hook one side up to the battery and hook the clip up to the cable.

 

A vise grips does a good job of holding the light to the battery post.

 

The test light should be brightly lit because of the current flowing threw it.

 

Look at the test light to see is it changes to being hardly lit between each step.

 

Disconnect the hood switch.

 

Open a door and disconnect the door switch. Open the other door and do the same thing.

 

Open the glove box and disconnect the light switch.

 

Now start disconnecting each fuse one at a time.

 

If the test light is still lit after checking each step above and all the fuses I would disconnect the headlight switch and then disconnect the ignition switch.

 

If its still lit bright start disconnecting under hood relays, fuses and fusable links.

 

If this still doesn't pinpoint the problem disconnect the firewall bulk head connecter.

 

By now you should have found which circuit has the problem. Check every thing on that circit to find the draw.

 

If not do the following.

 

If it went dim when you disconnected the bulk head connecter the problem would still be inside unless it has add wiring. If it stayed bright the problem is underhood.

 

Check which side you found the draw on because you coulkd have missed something.

 

The radio and the engine comuter have a slight draw which is normal. They are what keep the light lit dimly.

 

If you have a ammeter check the draw after you fix it and it should be about .25 amps..

 

Hope this helps.

 

:cheers:

[702_MJ]

That actually helps alot! Now i kinda have an idea on what to do. Thanks :cheers:

[HOrnbrod]

A test light will work also. I have chased voltage draws a ton of times.

 

Remove the keys from the ignitions and close both doors.

 

Disconnect the battery positive battery termal and hook one side up to the battery and hook the clip up to the cable.

 

A vise grips does a good job of holding the light to the battery post.

 

The test light should be brightly lit because of the current flowing threw it.

 

Look at the test light to see is it changes to being hardly lit between each step.

 

Disconnect the hood switch.

 

Open a door and disconnect the door switch. Open the other door and do the same thing.

 

Open the glove box and disconnect the light switch.

 

Now start disconnecting each fuse one at a time.

 

If the test light is still lit after checking each step above and all the fuses I would disconnect the headlight switch and then disconnect the ignition switch.

 

If its still lit bright start disconnecting under hood relays, fuses and fusable links.

 

If this still doesn't pinpoint the problem disconnect the firewall bulk head connecter.

 

By now you should have found which circuit has the problem. Check every thing on that circit to find the draw.

 

If not do the following.

 

If it went dim when you disconnected the bulk head connecter the problem would still be inside unless it has add wiring. If it stayed bright the problem is underhood.

 

Check which side you found the draw on because you coulkd have missed something.

 

The radio and the engine comuter have a slight draw which is normal. They are what keep the light lit dimly.

 

If you have a ammeter check the draw after you fix it and it should be about .25 amps.. Hope this helps. :cheers:

 

Nice detailed writeup Tim. I've done this a lot too, but much prefer using an ammeter in series w. the positive cable so I can actually see what the amperage draw is, especially if there are multiple drawdown faults. Even most el cheapo multimeters have a 0-10A scale that works well. :D

[TNT]

Nice detailed writeup Tim. I've done this a lot too, but much prefer using an ammeter in series w. the positive cable so I can actually see what the amperage draw is, especially if there are multiple drawdown faults. Even most el cheapo multimeters have a 0-10A scale that works well. :D

 

 

Thanks

 

I like the test light because I can tell at a glace if I found it. I've got a couple of good Fluke multimeters. I just find it easier to do with the test light and then verify the repair is complete using my ammeter in series. My Snap-On test light doesn't dim until its below a 1 amp draw.

[TNT]

That actually helps alot! Now i kinda have an idea on what to do. Thanks :cheers:

 

 

No problem. I enjoy helping out.

 

:cheers:

[702_MJ]

took the light out of the glove box just to see since the bracket is broke. LOL went to start it and see if it would just try to turn over........nothing. Dead dead dead. I was really hoping to get lucky. Guess ill do that procedure that TNT posted. If it would stop raining :fs1: Its beautiful at work(note 4 miles away) but when i get home its just raining. 2 weeks straight I'm going insane :mad:

[702_MJ]

k i got a question, why do power drains occur? :dunno: Course ill probly find out why when i fix the problem

[702_MJ]

Ok besides a JY does anyone know where i can pick the harness up for the headlight switch. LOL taking this time to do some stuff ive been putting off for a while. :cheers:

 

 

Thats it. All screwed up. Been like that for years though. Now another question is there a difference between the early switches and a 92' switch? Cuz i had a spare 92' switch and thats what i put in when the old switch shorted out. But i don't know if my dad switched the wiring so maybe that is the wrong switch, but its worked for 4 years :nuts:

[jtdesigns]

Ok besides a JY does anyone know where i can pick the harness up for the headlight switch. LOL taking this time to do some stuff ive been putting off for a while. :cheers:

 

 

Thats it. All screwed up. Been like that for years though. Now another question is there a difference between the early switches and a 92' switch? Cuz i had a spare 92' switch and thats what i put in when the old switch shorted out. But i don't know if my dad switched the wiring so maybe that is the wrong switch, but its worked for 4 years :nuts:

 

I was thinking Jeep used the same switch in all their vehicles. My 78 CJ had a switch just like my MJ's. Unfortunately, I'm not 100% sure if the connectors were the same...

[702_MJ]

Ok well i replaced my switch with my spare and i think it was shorted some where cuz when i turn on the key the parking lights don't come on any more. But i was just probing around the fuse box because the corner lenses don't have power and i want to fix that while its down. I probed the turn signal 20 amp fuse slots and the light was dim and i heard a click of a relay. Sounds like the same area under the dash of the one i replaced for the interior lights when you turn the lights on. LOL sorry for being a PITA on this topic but me and electrical just don't get along :dunce:

[702_MJ]

Ok since i noticed the clicking. I took out the fuse and i did the positive terminal to cable test and the light shines very dimly for a second then goes away. Then i put the fuse back in it turns on dimly. Note this is the TURN terminal in the fuse block. And thats the only drain i see. Maybe the battery has a dead cell. But i know those relays are not suppose to click when you test the TURN terminal. Any thoughts? :dunno: