Hi all.

I am experiencing a weird battery drain on my '54 WRX wagon.

One of the internal lights was left on for a few days and eventually the alarm started to intermittently go off. Upon finding the battery dead as a dodo I charged it overnight, turned off the offending light and carried on as normal.

Drove the car everyday to work for the next 3 days then I left it for a day and a half. I went out to the car tonight and I had forgot to lock it (luckily we live in a quite cul-de-sac). Thought nothing of it as we occasionally forget. Got in and it clicked instead of cranking. Not as flat as the first time, but dead enough. I thought I must have a parasitic drain. Decided to put the battery on charge and pop inside to do a bit of research on the interweb. Went out 30 mins later and the battery was fully charged and maintaining which I though was weird. Maybe it just didn't have enough for a crank, I don't know. I connected it back up and ran the car. Got 14.8V across the battery. Disconnected the negative terminal and the car continued to run, so I reckon the alternator is fine. The battery has 12.6 across it with the engine off.

I went through the normal testing for a drain. Disconnect negative terminal, tape down bonnet alarm switch, set multimeter to 10a and connect one meter terminal to the negative car cable and the other to the negative battery terminal. I then locked the car. The amps rose and then fell to around 0.04A which is normal. I then unlocked the car, this time the amps rose and fell back to a steady 0.5a WTF.

It seems my car drains the battery when it's not alarmed. Which, when you think about it, is better than the other way around. It just seems strange that it has never happened before the battery went flat from the interior light being left on.

Before I start pulling fuses, anyone have any ideas whats going on?

Also, are the interior lights supposed to come on automatically when you open the doors? Mine never have.

Thanks for reading my wall of text

 

Sounds like the complete flattening of the battery has signed it's death warrant. On my bugeye I had to give the battery a top up charge once a week otherwise the alarm would go off when the voltage dropped to low. Like you it did not take long for the battery to charge up and operate fine for a few days. There was no excessive drain on the battery. Fitted a new one and can leave the car two weeks with no issues, I now leave my battery charger connected when the car is not in use as it has a maintain facility keeping the battery at about 13.5 volts.

 

Regarding the interior light on my Bug the light switch is 3 position off,auto and on.

 

Thanks for the reply

It was dead again this morning so I think you are spot on. Going to call Halfords regarding the 4 year guarantee see what they say. I have no proof of purchase though.

I hope I have been that blind as to not see that light switch

Cheers

 

Have you got the RAC tracker fitted? These have been known to discharge the battery when searching for a signal.

 

I saw threads regarding this on my research, but I don't have a tracker. Just the standard Subaru alarm.

Cheers for the suggestion.

 

The complete flattening of the battery often causes one or more cell to "collapse" the inside no longer stays where it should, bits fall off and it doesn't hold charge.

Get it checked by a reputable electrical place, but a new battery will probably solve it.