VW Vortex - Volkswagen Forum banner
1 - 8 of 8 Posts

·
Registered
Joined
·
2,753 Posts
Re: battery drain (resyone1)

Start disconnecting items and measure the current draw...once U find the culprit it will be obvius...but how slow a drain are we talkin? If you have an aftermarket alarm or a stereo system it oculd be drained in a week or 2....
 

·
Registered
Joined
·
5,995 Posts
Re: battery drain (resyone1)

Quote, originally posted by resyone1 »
does anyone know the best way to find a slow battery drain?

Just drill a 1/16" hole in the battery. Any bigger and it'll be a 'fast' battery drain

Ok enough fooling around. There are several circuits that can operate when the key is off and those are the first thing to check.
Such as dome lights, panel lights, radio (does it have a circuit that's on all the time to save settings?) The clock. A stuck fuel pump relay could do it but I think you'd hear it.
You can pull fuses from these items to see if the drain stops.
Worn thru wiring can cause a leaky short circuit. Particularly in the steering column.
As previously mentioned alarm systems are notorious for draining batteries.
And it may simply be that your battery is not holding a charge anymore. I just replaced mine because it drained overnight. A bad rectifier in the alternator can drain it too.
Go to your local autozone etc and have the battery tested.
 

·
Registered
Joined
·
2,753 Posts
Re: battery drain (redvdubvert)

If you replaced the tranny, did U hook up all the grounds properly to it? If you have bad cables it coiuld be that the battery isn't draining so much as its not getting charged all the way up...
 

·
Registered
'81 Trek 614, '95 Ranger
Joined
·
12,256 Posts
Re: battery drain (resyone1)

Carlos,
Start with an ammeter in series between either battery cable and it's battery post, the ground side is usually easier. Don't try to start the car or run any high current loads while your ammeter is hooked up or you'll blow the meter's fuse if it has one, the meter itself if it has no fuse.
A maximum acceptable draw is 50ma for clock, radio memory and the like. There are some installers here that may suggest a higher draw is acceptable, let's wait and see their responses. 50ma was considered max allowable for a long time.
The actual amount of current your car is drawing can be very helpful in narrowing down the possibilities, there are too many possible combinations to try and list them all. Take a reading and post your results. this can turn into a lively technical discussion thread, there are many knowledgeable and experienced members on this forum and we never agree unanimously on anything!! (except maybe about Hondas!)

Ron
 

·
Registered
Joined
·
22,116 Posts
Re: battery drain (tolusina)

When you wire your meter in series, that is disconnect the batterys ground cable, attach the ground lead to the cable, then attach the positive lead to your batterys ground the meter is now in series, make the extension cable long enough to reach to the fuse panel. Now one at a time remove the fuses and note if the meter returns to Zero. You will have keep alive voltage (amperage) for your clock, and radio. As you pull the fuses out the last one that you remove that returns the meter to zero is where your drain is. Do not be fooled by removing the clock/radio fuse....
If your battery cables are resistive, (corroded internally ) They themselves can cause a battey to drain, as well as preventing it from charging fully.
If your battery cables are as old as your car, it is a good thing to replace them all. Measure the voltage between the battery with cables off shoudl be 13.5-14.6, then measure the voltage connecting the positive cable only (shouldn't drop). If it dosen't drop then measure the it with the ground connected (shouldn't drop).
If you see a drop then you need to look at the wires, is it dull copper? or Fuzzy dull copper, strip the insulation about 1 inch from the connector is it dull or fuzzy white? if it is dull copper, then you are probably okay fuzzy white replace. (remember to retape the insulation back.)
I did as one of the first (mods) things I did when buying my car. I have had very few (self induced) electrical failures. The second is that I re-wired the radio so that it could only be on with the switch.
I haven't been stranded once for a dead battery.



Modified by briano1234 at 8:32 AM 7-23-2005
 
1 - 8 of 8 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top