Hello. W209 CLK 320 cdi. Developed a serious battery drain issue, my DC tester shows it drawing 2.9 amps through the negative [earth] cable to body with nothing switched on. Apart from removing all the fuses and replacing one by one, I am wondering is there a likely common issue that I can home in on..? Thanks.
CLK Battery Draining
- Thread starter dryerman
- Start date
- Joined
- May 7, 2007
- Messages
- 20,007
- Car
- Lexus RX450h F-Sport with Takumi Pack 2020
The electric block heater is prime candidate. They go short circuit and drain the battery. There is no fuse. Disconnect the thick supply cable and retest. The thin cable is just a control feed.
If it is the culprit just leave disconnected as they only operate when there is a surplus of charge from the alternator and I never noticed it work on my C270 in the 9yrs I had it
If it is the culprit just leave disconnected as they only operate when there is a surplus of charge from the alternator and I never noticed it work on my C270 in the 9yrs I had it
That's great thanks. Not aware of the block heater, can you guide me to where it is located?
- Joined
- May 7, 2007
- Messages
- 20,007
- Car
- Lexus RX450h F-Sport with Takumi Pack 2020
On my 5 pot it was midway down on the engine block nearside. Just a square slab bolted on.
Petrol Pete
Hardcore MB Enthusiast
Not your car but a very good explanation how to fault find properly.
grober
MB Master
Other possibility is a short circuited diode in the alternator- repair is not easy- best solution is a reconned one if its that?
