My wifes C4 drains its battery when parked. Suggestions as to how to solve this problem would be appreciated.

 

Are you handy with a multimeter?
Take the negative battery cable off.
Hook the meter set for AMPS between the two.
Wait for interior lights have gone off.
A few milliamps of drain is normal in any vehicle.
If it is more than that, start pulling fuses one by one and checking to narrow it down.

 

Tried this prior to asking forum. read 10-12 MA Must be intermittent, i e turns on/off?? new battery installed when vehicle purchased. prior to purchase, car had been parked for 12 years.
A real life barn find. only 32k miles.

 

How long is the car parked before it kills the battery?
Seems pretty low chance its an intermittent parasitic drain.

 

battery is depleted in approximately eight days.

 

I once had a motorcycle that had a weird charging issue. In that case it ended up being a bad connector between my stator (alternator) to my voltage regulator/rectifier. When the volt meter was put down, everything looked fine, but after about three days of riding the battery would be dead. Replaced the connectors in the wire harness to the regulator and I was back to normal.
I'm taking it that in your case the car is not being driven over the eight days though, huh? All I can think at this point is to clip your volt meter between your negative connection and watch it. Do you have a wireless camera or a baby monitor with video to check here and there for a spike in amperage drain?

 

Ever get any traction on figuring out the problem?

 

Put the battery on a real charger overnight.
This will bring the new battery up to full charge.
Even a new battery needs a charge. I assume you are not driving the car very much.

After topping off the battery, it should last at least a month.
Other things.
When the engine is running, check the battery charging voltage with all lights off, heater off, etc. You should see a value between 14.0 - 14.9.
Now turn on the lights and heater.
Voltage should still be between 14.0 - 14.9.
Miles

 

Thank you for your response.
Battery was fully charged
Alternator output was checked (14.4 volts)
Car refused to start, New problem. Bad fuel injector found. Not obvious to me how problems could be related.
Will up date thread subsequent to injector replacement.

 

1 bad fuel injector will not keep the car from starting.
Check all Fuel injectors.
Check plugs,
Check Ignition. Do you see sparks on all 8 cables?
When was the last time the Optispark/coil/Ignition control modules were replaced?
Replace fuel filter.
Check fuel pressure, what is the pressure for each combination.
Key On, engine off
Key On, engine running at idle.
Key On, And Off after 5 minutes.