I've got a 1990 Teg, XSi (B16A engined) and I've been having trouble with the battery power. It all started with a dead battery for no reason, so I had the alternator tested and that was all ok, then I got the battery tested, and found that it was shot. Then I bought a new battery, and the car was running fine (driving it every day). Then over the Christmas holidays I went away, and used another car. A week and a half later, when I get back, and the battery won't start the car, coz it's almost stone dead. Is this a problem with a circuit closed and slowly draining the power? Or something else? Anyone got any ideas?

Mike

 

First I'd check for a circuit that's still on when you go away. If it's OK overnight but drains over a week, look for a pretty small load. Glovebox or trunk light stays on? Alarm or amplifier that stays on? If it were any of the outside lights (parking lights), I think it would go dead faster than that...

If the battery wasn't new, I'd say disconnect it next time you can park for several days. Then you'll know whether it's an internal short in the battery.

 

Yeah I checked all the main ones (parking lights, internal lights, the stereo doesn't work right now, I'm in trasit of getting a new one)

Does having the alarm curcuit going use up power enough to drain the battery in a week and a half?

Can you not test for an internal short with a new battery?

 

alarms do not use enough power to drain it in a week

 

You can always test the current with a multimeter with the engine and all electrical devices off. If it's showing any current then start pulling fuses until it goes away. That way you'll find what's causing the parasitic draw. I've heard of diodes going bad in the alternator causing a constant draw of 2-3 amps. That's good enough to kill a battery over a short period of time (a week), but not overnight.

 

Cool that sounds feasable. I know this prob sounds dumb, but what should I connect the multimeter to? Like, if it's an appliance or component that uses a few wires. (I'm not too hot on car electrics.)

Would an alternator test show up a bad diode?

Thanks for the help

"As far as I can taste, it's all clean, bold, and naturally brewed."
"Chivalry: The philosophy of a man to defend a woman from every man except himself."

 

A bad diode can show up in an alternator test if they pay attention... If they watch the output on an oscilloscope they should see it. If they don't, a bad diode will normally cause the alternator output to be lower than it should be.

Measuring current draw...
Take off the negative battery cable, then hold it back against the battery post. Set your DMM to measure current, 20a or autorange. Put the (-) lead on the battery post & the (+) lead on the cable. After holding it like that for maybe a minute, pull the cable away from the post leaving the meter hooked up. Now ALL the current that the car is using flows through the meter.

If it's about zero you can switch down to a lower range. If you have to move the meter leads, then you have to repeat the procedure of holding the cable on for a minute or so.

The reason for holding the cable to the post for a minute... Since you disconnect the cable to begin with, some stuff like the alarm has to 'reboot'. You don't want that high current to blow the meter's fuse...

It shouldn't be zero, because of the clock & radio presets & stuff like that. I don't know what's normal, maybe 20 milliamps (0.020 amp)??? If it's too big, start pulling fuses to help you find what's using the power.

 

Thanks for the advice JimBlake. I did what you said, and tested the current, but it's only at 0.2 when set at 200m on my DMM. (therefore 0.2 at 200m). Is it DC or AC current? (I'm not a guru at car elecs!!)

That reading sounds too small to be draining power over 1 week. (??) So yeah...Weird problem. It's definitely not the alternator because it's charging the battery fine when I drive every day/2 days. It's just when the car has been sitting. It's not the battery, I let it sit unconnected for a week and it was at full power this afternoon when I did the check.

Another problem with my Teg: If it hasn't been driven for anything over 2 hours, I can start it and drive away, etc. But when I stop it for about 5 minutes or something, come starting it up again it'll start, but then it will cut out almost immediately afterwards. Then I'll be cranking away at the starter for ages, and it'll start again, but then die immediately. If I'm lucky, another 5 minutes I'll be doing this and it will run. Does this sound like fuel pump/lines? Or just fuel filter? (The car hadn't had any maintainance for about 40,000 kms (25,000 mi) when I bought it, hence an obviously clogged fuel filter and other stuff.)

 

You should set it for DC amps. Some meters display 200 mA as 0.200 even when they're set at the 200 mA scale. (So that's like full-scale.) Set the next higher range & see?

It's hard to believe you could actually measure 0.2 milliamps with a normal multimeter. That's really small, so that's why I suspect it's 0.2 amps (200 mA). You'd like it to be 0.02 amp or less, so start pulling fuses.

What's a normal car battery, 40 amp*hours? So 200 mA would drain 4.8 amp*hr each day.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by integraboy &raquo;</TD></TR><TR><TD CLASS="quote">... The car hadn't had any maintainance for about 40,000 kms (25,000 mi) when I bought it, hence an obviously clogged fuel filter and other stuff.</TD></TR></TABLE>More likely fouled plugs or bad plug wires. Maybe a sticky FITV? If the fuel filter were clogged, then it wouldn't be able to rev after it's warmed up.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by calxtreme &raquo;</TD></TR><TR><TD CLASS="quote">alarms do not use enough power to drain it in a week</TD></TR></TABLE>IF they're working correctly...

 

How do you post pictures?? (I've got one that might help with this thread)

FITV is what...?


Modified by integraboy at 5:48 PM 1/19/2005