We just got a Crossfire 2005 convertible with 14,000 miles and the Interstate battery died twice. The first time we jump-started it and took it to Batteries Plus to ask about the battery and they tested it and said it was probably something to do with the electronics but that the battery was fine and it just died again and both times it was not being driven for about a week or two so we don't understand why because the battery is only 6 months old

Thanks for any help with this, Jim and Jen

 

After driving the car you may have a drain due to issues with car. Easiest thing for you is to remove battery terminal while not driving to see if a week REST has an effect or not.

Beyond that you could pull the + terminal and measure the current draw with doors shut and car OFF. That requires a meter and experience. I park for weeks and have an EXTERNAL connector by windshield blade on passenger side, for a TRICKLE charger when stored. JUst remember to pull the trickle connector when backing out of parking space-garage. Woody

 

I concur with Woody on this if you've had the battery tested by Batteries Plus. There must be a small current draw from the car while sitting idle. As Woody stated, this can be verified fairly easily. If you don't have the knowledge to do this, take the car to a local independent service shop that handles Mercedes-Benz cars & have them diagnose your issue. I'm not saying to avoid a dealer for this (most of us don't take our cars to a dealer), but if you can find a M-B dealer that would look at your car (quite a few won't look at Crossfires), I would recommend that over going to a Chrysler dealer. An independent M-B service facility is probably your best bet.

 

Can a bad alarm siren {leaking batteries) cause a draw like this?

 

We finally got a kill switch installed which solved the problem. If anyone is interested. we are selling the car now as it was husband's dream car and he passed on 8/25. It has 16,562 miles, LoJack, and a new alternator and radiator fan assembly. Starts right up. A real creampuff. 20 years old as of January. Convertible top seams need reglued but is kept under custom car cover. If it was automatic wife would keep it. Hubby wanted the stick shift. Thanks.

 

You might want to list it in the Market Place with photos and more info including coupe or roadster and price?

 

Thank you. Yes, I will list it in the marketplace..

 

No, it swept the problem under the rug. The car still has an electrical problem. This is very likely a bad siren module, but it can be a leaky diode in the alternator, water damage to the CLP/SSM, or a failing FCM. (Or any of a NUMBER of other items.) It is very likely that, eventually, this issue will rise to the surface (locking system will fail, fan operation will cease, A/C will refuse to work, alternator fails, etc.)

At least you are selling the car with a sign that says, "This car has an electrical issue", in the form of the kill switch. So, you ARE being (unintentionally) honest.

Finding excessive battery drain is not that hard to do, it's just that almost NO "mechanics" even try to learn how.

 

I am sorry for hijacking this thread, but I have a similar issue. My 2005 SRT6 convertible has a parasitic battery drain issue. I individually removed each of the fuses in the big box next to the battery...no impact. I then opened the small box in front of the battery. No impact with the two 50 amp fuses, but disconnecting the 200 amp fuse the current went to zero. What is the next step? Thank you!

 

Follow the procedure below, there are a few items that are not fused OTHER than by the 200 amp fuse - those include the ICM and power seat relay.
In such a case, you must dig into the underhood fuse box and find the cable connected to block 100 that has the current in it, and follow that cable to the item that is at fault.
In extreme cases, you must simply leave that cable unconnected until you figure out what it powers, since all cables at SB 100 are red and unmarked.

But this is RARE, only ONE time did I encounter the drain in an unfused red line at SB 100.