A914MAN

I got my '91 C2 Targa in May of last year, and in July (same year) I had to replace the battery, which was only 18 months old (having been replaced by PO). I've had to replace it again, free warranty though.

Within the past few months there have been several occasions where the battery was too low to start the car, I gave it a boost, and drove it for a while and no problem as long as I drove it once a week. Within the past week I had to boost it twice to get it started, even though it had only been three days since I drove the car. Sunday it was low, and I took it on a 200 mile trip, starting and stopping 4 or 5 times without issue, today it was really low and I got the free replacement.

Do these cars have a problem eating batteries? I have put a new stereo, but that was installed after my first replacement.

It's obviously charging OK.

Marine Blue

misterbeverlyhills

Check your door switches, took me a few hundred dollars and several months to find that was my problem. It is cheap once you locate the issue.

Tarek307

2nd that on door switches, also check the HVAC fan and make sure it isn't always on, and the light under the front bonnet, if you are on your 3rd battery its definitely not the batteries that are the issue

newsboy

Is your alternator putting out the correct charge? Should be about 13.5- 14 volts at idle.

A914MAN

Thank you gentlemen, I'll look into all suggested solutions!

s4magman

Don't forget the glovebox light - you never notice if it is on.

Rocket Rob

Start by checking the basics
1) Are your grounds clean? Check at both the battery and the starter
2) What is your charging voltate with the engine idling? It should be 13.5-14.0 volts
3) Have you measured what the current draw is with everything off? It ought to be 40-60 milliamps. If its higher, then you need to try to isolate it.

As stated above, if you are storing for a long period, a battery maintainer is critical or disconnect the battery.

Railmaster.

Just want to explain that the "HVAC" fan is the CCU fan located inside the CCU (climate control unit), should run like ten minutes after You turn off the engine. If it does not shut down it will drain the battery but there is a realy inexpensive DIY fix for it!

Lean towards the CCU and You will hear the fan inside it!

Trader220

I agree with others, its almost a guarantee that its a door switch. Obviously try the drivers side first since it was used more than the other side. Cheap easy fix, no more battery issues.

Vegas993

To test your door switch, shut the car off and open your door, then try the window switch. It should NOT work, if it does, bad door switch.

johnsopa

Oh, wow, I thought this was a feature. Seriously. If this is true, then my door switch is bad, too.

Wouldn't my interior lights stay on, as well?

FlyinTomato

could it be the clock? the clock needs juice too.i always suspect it's the clock.

I can't leave my car for 3 days. battery will be dead. I am parking at a underground garage so it's really hard for to work on it. I have a battery disconnect switch, it's my temp solution for now. disconnecting it if I know I am not driving the car for a few days.

Vegas993

Lol, it's true. I went through a couple of warranty Bosch batteries before I figured it out myself.

The interior lights are a whole different can of worms, they light itself is a rocker switch. I've found it best to leave them off.

911URGE

Former 964 owner. Agree with checking the door switches. Another thing to check is the radio green wire issue. If not properly isolated it can cause a battery drain.