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Location:
Dandenong Ranges, VIC
Registered:
July 2004
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short circut?
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Sun, 02 January 2005 23:20
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after disconnecting my (TA22) wiper motor and trial fitting an RA60 unit, the battery went flat in the space of about an hour. it didnt seem to be dying until a couple of hours after i stopped working on the wiper motor, but while i was re-fitting some interior trim i noticed the interior light wasnt working etc.
i disconnected the +ve lead off the battery to charge it, and when i went to put it back on the next day, sparks fly between the terminal and the lead every time they touch. the battery is now dead again.
i checked all the fuses and disconnected them one by one and all at once etc. with no change apparant. the wires that are now exposed with the wiper motor removed are not contacting each other, nor are any other wires that i can see.
whats goin on?
i need the car fixed by tomorrow 
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Location:
brisbane
Registered:
October 2004
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Re: short circut?
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Sun, 02 January 2005 23:35
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sparks fly = large amount of current, so yeah it
is a short circuit. the short circuit may bypass the
fuse which seems quite likely in your case.
well it only happened when you changed stuff on
the car, so start looking at what you did first.
electrics is always a bitch, if you have a few
positive leads connecting to the positive terminal,
id disconnect them all and test each one. then you
can narrow it down to a big circuit.
then you'll have to find the smaller circuit.
as for testing, you can use a 12v light bulb with wires
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Location:
Dandenong Ranges, VIC
Registered:
July 2004
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Re: short circut?
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Sun, 02 January 2005 23:42
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cheers, yeah ive got 2 leads connected to the +ve terminal, both of them spark...
got the RWC booked tomorrow morning, so its gonna be a long night i think 
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Location:
Brisbane
Registered:
February 2003
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Re: short circut?
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Mon, 03 January 2005 04:22
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pull all the fuses ... connect them back one by one and do a spark test (touch the 2 leads to the + terminal of battery) after reinstalling each one - you'll then know which circuit is pulling lost of current.
do that same from heavy duty compenents like the starter, alternator and ignitor.
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Location:
Wollongong
Registered:
November 2004
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Re: short circut?
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Mon, 03 January 2005 05:39
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Disconnect the -ve lead...
Put on the +ve lead...
Reconnect the -ve lead...
Positive lead always gets put on first... ALWAYS!
Sparks flying is just the factor that something is most likely turned on, turn off / unplug your stereo, make sure the Ign is turned OFF...
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Location:
Dandenong Ranges, VIC
Registered:
July 2004
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Re: short circut?
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Mon, 03 January 2005 08:43
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well, traced it down to what seems to be an internal short in the battery. will try a new battery tomorrow morning.
i just had an ignition issue that meant i spent alot of time cranking while trying to diagnose faults, hence lots of flat batterys and lots of recharging. does anyone know if this internal short could be due to repetitive re-charging of the battery?
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Location:
Brisbane
Registered:
February 2003
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Re: short circut?
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Mon, 03 January 2005 09:14
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could be - automotive batteries are not designed for continuous deep cycling (a varying or constant load is put on battery taking it down to zero charge).
marine and off-the-grid power supplies often use batteries specifically designed for continuous deep cycling.
a cheap automotive battery is often permanently damaged after only 4-5 such events.
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I supported Toymods
Banned User
Location:
Brisbane
Registered:
May 2002
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Re: short circut?
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Mon, 03 January 2005 09:44
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| Kyosho wrote on Mon, 03 January 2005 15:39 |
Disconnect the -ve lead...
Put on the +ve lead...
Reconnect the -ve lead...
Positive lead always gets put on first... ALWAYS!
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errr what?? I think you are getting things mixed up with jumper leads 
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Location:
Dandenong Ranges, VIC
Registered:
July 2004
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Re: short circut?
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Mon, 03 January 2005 12:41
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yeah, couldnt quite figure that out...
connecting the +ve lead first would only ionise the circut yeah?, thats not really an issue is it?
i rekon ive probably charged that battery 30 times , so i guess ive done well out of it  i'll be more careful with the next one, thanks guys.
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Location:
brisbane
Registered:
October 2004
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Re: short circut?
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Tue, 04 January 2005 06:42
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long cranking! never crank for ages!
cranking the starter = lots of current, long time =
hot wires = melting of wires/devices = short
and general auto batteries are not designed for deep
discharge cyles so you could have wrecked it
no matter which way u put on leads they shouldnt spark!!
only a very tiny bit if u have a clock/small device running
the reason of putting on leads in this way and that is because
the negative is connected to the chassis (earthed)... so...
undoing terminals
take off -ve first then +ve
connecting
put on +ve first then -ve
then u wont get shocked by the chassis (which is connected
to the negative) if you touch it when holding the positive
terminal
or
cause a short if the +ve terminal touches the chassis.
you can still be shocked by getting between a post and its
terminal but thats common sense.
zzzzzzzzzzzzzzzzzzzzzzzzzzap!
i never remember the order lol i just remember to kill the chassis first when disconnecting and activate it last when reconnecting and its all sweet
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I supported Toymods
Banned User
Location:
Brisbane
Registered:
May 2002
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Re: short circut?
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Tue, 04 January 2005 07:06
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Umm no.
The only reason for connecting the positive lead first is so that when you make the final connection, if a spark does happen it wont be near the flammable gases coming out of the battery! However doing this can cause other problems. If you connect the positive lead first, you may cause a spike to go directly to your ECU which will then blow its top and possibly other things along the way.
In all my cars and all the cars I work on for a living I always disconnect the positive first and reconnect it last. I do however make sure there is plenty of fresh air passing the engine bay clearing any gases.
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Location:
Bottom of the hill, Sydney
Registered:
April 2004
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Re: short circut?
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Tue, 04 January 2005 09:09
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| Cool1 wrote on Tue, 04 January 2005 18:06 |
The only reason for connecting the positive lead first is so that when you make the final connection, if a spark does happen it wont be near the flammable gases coming out of the battery!
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Are you saying that the cells near the negative terminal of the battery don't put out any gas or do you mean to connect the negative lead at the chassis as your final connection.
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I do however make sure there is plenty of fresh air passing the engine bay clearing any gases.
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Excellent advise when working with a battery that is being charged or has just come off the charger.
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If you connect the positive lead first, you may cause a spike to go directly to your ECU which will then blow its top and possibly other things along the way.
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How does this happen. Surely for a spike to occur from the battery being connected it needs to have a complete path back to where it came from. Therefore no current will flow from the battery unless both terminals are connected. So why is it different if you connect the positive first or last. Also a spike is caused by excessive voltage so how do you get this from a 12 volt battery.
Voltage spikes while jump starting are a different story. These are caused when the flat battery is connected to a car that has the engine running. The alternator on the car that is running senses the extra load from the flat battery and increases its output which can cause the voltage to rise to a level which can damage electronics. This rise only occurs for a split second but is generally enough to fry things.
When disconnecting a battery I always do the negative first. This way if you touch the body of the vehicle with your spanner you won't get a spark. When you come to disconnect the positive the circuit is cut so again if you short the terminal to the body with your spanner there won't be a spark. The reverse applies when reconnecting, positive first, negative last.
Sorry for going way off topic and sounding like a prick. I'm not trying to start an argument, just clearing up what I believe to be wrong information.
Brad
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I supported Toymods
Banned User
Location:
Brisbane
Registered:
May 2002
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Re: short circut?
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Tue, 04 January 2005 09:20
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| BradW wrote on Tue, 04 January 2005 19:09 |
Are you saying that the cells near the negative terminal of the battery don't put out any gas or do you mean to connect the negative lead at the chassis as your final connection.
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Yes connect the lead to the chassis last.
Capacitors, discharging capacitors and different voltage potentials are some ingredients to causing a spike. Static does not need a connection to ground to cause damage.
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Location:
Bottom of the hill, Sydney
Registered:
April 2004
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Re: short circut?
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Tue, 04 January 2005 09:31
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| Cool1 wrote on Tue, 04 January 2005 20:20 |
| BradW wrote on Tue, 04 January 2005 19:09 |
Are you saying that the cells near the negative terminal of the battery don't put out any gas or do you mean to connect the negative lead at the chassis as your final connection.
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Yes connect the lead to the chassis last.
Capacitors, discharging capacitors and different voltage potentials are some ingredients to causing a spike. Static does not need a connection to ground to cause damage.
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So your refering to a spike caused by static electricity put into the system from touching the positive lead. Point taken 
Brad
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Location:
Wollongong
Registered:
November 2004
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Re: short circut?
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Tue, 04 January 2005 09:41
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| Cool1 wrote on Tue, 04 January 2005 18:06 |
Umm no.
The only reason for connecting the positive lead first is so that when you make the final connection, if a spark does happen it wont be near the flammable gases coming out of the battery! However doing this can cause other problems. If you connect the positive lead first, you may cause a spike to go directly to your ECU which will then blow its top and possibly other things along the way.
In all my cars and all the cars I work on for a living I always disconnect the positive first and reconnect it last. I do however make sure there is plenty of fresh air passing the engine bay clearing any gases.
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If you have had much to do with chemistry, you'd realise that connecting the +ve first will do nothing, the electrons (-ve) flow from -ve to +ve, therefore, your electrical flow is actually from -ve to +ve, the reason for this, when a particle is ionised, it looses the electron, (-ve) which moves to an unlike pole (+ve), now to move a proton, you would need to pull apart the nucleus of an atom, when you break an atom, god oh hell some energy can be let loose (Think nuclear fission)
The strength in a bond between nuetron and proton is enormous, therefore only the -ve moves freely, therefore, the real way electricity flows is from -ve to +ve, although, scientists still say it flows from +ve to -ve for simplicity...
Also, if your Anode breaks down, it can short the battery...
[Updated on: Tue, 04 January 2005 09:44]
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I supported Toymods
Banned User
Location:
Brisbane
Registered:
May 2002
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Re: short circut?
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Tue, 04 January 2005 09:45
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Forgive me while I go tear up my Diploma and try and forget the last 8 years I have worked in electronics engineering.
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I supported Toymods
Banned User
Location:
Brisbane
Registered:
May 2002
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Location:
Wollongong
Registered:
November 2004
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Re: short circut?
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Tue, 04 January 2005 09:47
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| Cool1 wrote on Tue, 04 January 2005 20:45 |
Forgive me while I go tear up my Diploma and try and forget the last 8 years I have worked in electronics engineering.
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I wasn't trying to be rude or anything... No need to take offence...
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I supported Toymods
Banned User
Location:
Brisbane
Registered:
May 2002
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Re: short circut?
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Tue, 04 January 2005 09:48
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I changed my mind. I feel sorry for you.
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