Battery Problem

[vl1234]

My battery is draining and it's given me the #$^%!

It started last week, the battery light was on for a few days and then the car wouldn't start. Replaced the battery. Still kept draining, so I checked the brushes on the alternator and they were almost non-existent so i replaced the regulator and brushes. Kept draining, so I replaced the terminals on the battery. I keep charging the battery up and it keeps draining down. I've checked all the interior lights to see if something and they're all off. I can't think of anything else, any suggestions?

It's a VR series 1 btw.

 

[WAGON MAN]

Have you checked to see if your boot light is still on when the boot is closed?

 

[redvr]

how long is it taking to drain the battery???? and is the alternator producing power??

 

[Not_An_Abba_Fan]

Check the output from the alternator, also the main charge wire, see if it has melted the plastic coating. If so cut it back and fit a new terminal. Sometimes the alternator fries internally and it requires replacing.

 

[vl1234]

Have you checked to see if your boot light is still on when the boot is closed?

Yep.

how long is it taking to drain the battery???? and is the alternator producing power??

Generally takes overnight to drain.

Alternator has been tested and is fine.

Check the output from the alternator, also the main charge wire, see if it has melted the plastic coating. If so cut it back and fit a new terminal. Sometimes the alternator fries internally and it requires replacing.

Checked all the wiring, appears fine.

I think I might have to refer this problem to an auto elec.

 

[Not_An_Abba_Fan]

Silly question but did you replace the battery with new or second hand?

 

[hako]

One of the diodes inside the alternator may have failed allowing the battery to drain back thru the alternator. This fault will also reduce the alternator output.

 

[Immortality]

if you have access to a multilmeter, pull each fuse in turn and hook the multi meter into the circuit. you'll soon find the one playing up and then you gotta figure out why

 

[kopper69]

If you have a multimeter, just put it on the battery with the car off, start the car and check the voltage with the car running. Tell us the figures and that may give us a starting point. Another test you can do is to disconnect the battery when you are home and finished driving for the day, reconnect it in the morning and see if she starts. If she goes fine after you disconnect the battery, you will know that something is draining her. If she still struggles, you will know she is not being charged right.

If you do have a multimeter and you want to check if there is a circuit draining the battery, you will need to take immortality's advise and disonnect fuses/relays. You will need to watch the current though, which means connecting the meter in series. It is possible to watch the voltage and work it out, but wont always work, and isnt as easy. The only problem with trying to watch the current used, is that most meters only like about 10A. If there is a circuit that takes over that, even spikes over, it can blow the fuse in your meter, and she wont measure the current until you replace the fuse.

If you want some pics or more detail, let me know.

 

[vl1234]

One of the diodes inside the alternator may have failed allowing the battery to drain back thru the alternator. This fault will also reduce the alternator output.

Thanks for all the tips!

Turns out that one of the diodes in the alternator failed - replaced it with a recod unit from the wreckers and it's now working fine.

As hako said, the battery was not getting correct charge and when the car was off the battery was draining back through the alternator.