Electrical leak

jeepgeek2002

NAXJA Forum User
Location
Jax FL
Came back from Callalantee this weekend, monday the battery is dead..Jump started it up..let it charge back up.. then drove around monday. stopped and started fine.. this morning.. Dead.

Whats the 1st steps to do when you get a battery drain?
replace battery...
check for loose wires..
i read somewhere about a test light and removing ground?

ideas?

Mark
 
alternator is working..its chargeing the battery..
its been running solid for a whole time i ve owned it.. this is the 1st time its ever done this..

more ideas?
 
i read somewhere about a test light and removing ground?
This would be my first step in looking for a parasitic drain, but would use an ammeter, even acceptable drain level will keep a test light illuminated.
Call me, I'll walk you through it, Its a relatively simple process.
Knowing about your recent door latch issue, I would blindly guess it's related to alarm/power door locks, but from my experience it's most commonly aftermarket radios wired to an unswitched power.
 
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You can take it to some place like advance and they can tell you how much drain there is on the system.
Most of the BSA testing equipment have ammeters capable of 1A resolution, perfectly acceptable for testing battery capacity, starter draw, alternator output, etc.
You will most likely need something a little finer, say in the 10mA(.010A) range. Some digital equipment may have the capability, but most part stores have relatively lower end equipment. A multimeter with a 10A capacity ammeter is really all you need.

It's pretty simple test, but does assume alternator and battery are in good working order.

You need
a] Ammeter (10A capability, minimum 10mA resolution, digital is prefered, but analog will work on older vehicles with simple wiring)

b] Jumper wire with alligator clips large enough to grasp battery terminal

c] Beer (I prefer High Life in cans but test will work equally well with pussifed beers as well)

d] Friend (preferably one that is less of an an alcoholic than you) This is optional, I can perform this test and I have no friends, just takes a little longer, and you tend to cry yourself to sleep.

Test Procedure

Open beer

Turn off all electrical consumers (including ignition and remove key)

Leave aftermarket radio face inserted in radio

Close all doors except driver, which you need open to access fuse panel,

Depress door jamb contact switch on driver(may need to false latch door as well, depending on make/year)

False latch hood latches (if you have automatic underhood light, alarm sensor, etc.)

Disconnect POS+ battery cable

Connect jumper wire to POS+ battery terminal and to POS+ battery cable clamp

Arm alarm

If vehicle is later model (1990 euro, 1996 asian, 1998 domestic, roughly), you may need to wait until active control modules enter sleep modes, this can take as much as 60-90 minutes on very late vehicles

With ammeter in 10A range connect leads of meter in parallel to jumper. In this test polarity isn't important, it will just read negative, the measument is absolute(ie. -1.6A=+1.6A, draw is 1.6A)

The current reading on meter is roughly 1/2 of actual draw (jumper wire splits circuit)

If the reading is over 5A; DO NOT DISCONNECT jumper wire (10A fuse in meter and/or ammeter will fail)

Disconnect jumper wire while leaving meter connected(must maintain contact at all times, ie: if you knock it off, start again)

Meter reading is now actual draw/parasitic drain

50mA(.050A) would be quite a lot for a simple wiring system, On a early XJ with only a clock and radio memory as draws, 25mA would be a more reasonable number, very late european vehicles are regularly over 500mA

Aftermarket alarms and radios are the unknown variable (no one ever has the manual) I've seen radios draw upward of 50mA and alarms over 250mA.

If you are under 30mA(.030A) your problem lies elsewhere. (battery is dirty, electrolyte low/weak, ie: battery problems)

Now that you know the actual draw, start removing and replacing fuses until you find the draw, indicated by a reading change when fuse is removed/replaced. This is where a friend can be useful, and you always need someone to hand you another beer.

If there is no change with any of the fuses, check relays.

If still not found, disconnect alternator wiring (charge wire and field control), ECM connector, Trans module, etc.

If still not found, and you have a manual transmission on an X/MJ check your fuse panel carefully for clutch master cylinder leaks.

If still not found, you may need more help than someone can give you on the internet. Recheck your steps.

When you identify the fuse through which the draw is passing, you have a few options:

A] consult FSM/wiring diagram and identify all consumers on said fuse

B] guess

C] since it was the radio fuse, rewire radio

You can then continue further down the harness and identify the consumer that is remaining active.

The short list of common draws I have seen:
Aftermarket alarms and radios <-- 90% if they are present
Factory radios
glovebox, trunk lights (failed switch/mechanism)
ECM/other module internal failures
Door latch sensors

This is by no means the endall for a no crank/no start, but if you have narrowed it down this test can point you in the right direction.

There are a few steps that can be skipped/eliminated/expanded depending on vehicle type, year, make, etc. X/MJ's span the time from early FI systems into late body control setups, so there are variables.

As with all electrical testing, don't let the smoke out, it never goes back in. This is the Internet, I am not responsible for your actions, Luckly this is also America and you probably aren't either.:us:
 
you lost me after open beer...

lol

Mark
 
hey my postive battery wires are all over the place.. is there some kinda jb weld i can put on them to keep them inline..?

can i use JB weld?lol

Mark
 
I would say no. I am not sure if JB Weld is rated to handle current and how it reacts when it heats up due to electricity.

Best bet is to buy a set of cables from 5-90. They are sex.
 
I may have found it..
My electric seat button was stuck in the down position..
it was pure luck that i looked at it on the passanger side seat.

mark
 
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