briansbrowns

Hoping someone can help me here. My battery keeps losing it's charge. I have pulled radio fuse and let sit, door locks and let sit, etc. I have a bad electrical draw and cannot locate it to save my life. The MB shop could not find it either. Any suggestions as to what I might do? Thanks for all the help in advance!!!

e1000

check your seat modules.

briansbrowns

Do you think if I just disconnect them it would be OK or should I pull a fuse? Not really sure how to read them out electrically.

samaritrey

just unplug them

briansbrowns

Thanks I will try that tomorrow and see what happens over the course of the next week. Got to trickle charge the battery first so I can get it in the garge though.

W203E35

Check out Mike's thread. This is how to fix the seat module that drains the battery.

https://mbworld.org/forums/c-class-w...ml#post3068555

danev6972

Same here. Mine is getting worse. It used to take a few days of inactivity before the car drains, then it went down to two days. Now it's overnight.

The the seat module wire have pulled/disconnected for a while now but it does not make a difference. I don't know if it still drains while disconnected.

Earlier today I pulled the power seat and cigar lighter fuse and see what happens...Pulling each fuse to find the drain will be my next move.

Carsy

I am pretty sure the 204 computer can show amps drawn.

If the 203 has the same it may help when pulling fuses to isolate the problem.

Glyn M Ruck

Seat modules or A/C sensor fan in the overhead pod.

Xhale707

Glyn A/C sensor fan in the overhead.. I believe mine runs all the time.. Ill be sitting in my car and i can hear this faint noise coming from up there. Should i worry?

Glyn M Ruck

Only if it does not shut down automatically & runs your battery flat.

mikey1011

hey dunno if you fixed your problem or not. But here is a way how I pin point the problem. Disconnect the ground from the battery. Get a multimeter, adjust it to amperage, and connect in series to the battery. You should get a reading of less than 0.1 amps, usually around 0.07a.
There is a delay, so wait about 20 to 30 sec for everything to settle down, and get the reading. Start by pulling fuses one at time and see where that leads to...no pun intended lol

hope that helps
Mike

danev6972

I'm also curious how the OP made out.
Thanks for the tip Mike I'll do my "checks" this weekend.
As far as my troubles:
1st Took out fuse #s 27 & 38 Seat Adjustment Driver & Passenger/ #47 cigar lighter(Glove light)...Did not work. Not it.

2nd Fuse 3 & 9 Dome lights, # 64 Radio (aftermarket w/amp & subs)... I'll find out tomorrow a.m. if it works.

Battery: Autocraft Titanium 02/2009
Voltage: 12.31 sitting/OFF, 14.19 running @ idle, 13.92 running idle w/ all "creature comforts" turned on.

danev6972

Hey guys don't know if you have seen this.

http://www.youtube.com/watch?v=GtJMHSY7hso

danev6972

Morning came & the car barely started...will check again on the weekend.

Carsy

How old is the battery ? . It could be an internal battery fault

You could always c/o to another battery to see whether you have the same symptoms.

Also disconnecting the Neg terminal after use & reconnecting after a day or two to see whether the battery has discharged.

danev6972

I'm going to buy a new battery tomorrow and see what happens...
Bought the batt in 2009.

Thanks.

Carsy

It is almost new so a little diagnosis is needed before you spend your hard earned.

I would take it back to where you bought it & ask them to check it for problems.

It may still be under warranty .

Good luck & let us know how you go.

Carsy

briansbrowns,

Any luck in solving your problem?

Glyn M Ruck

Dane - make them load test the battery.

pcy

Load testing can be done at auto parts stores for free.
Or,you can buy your own load tester for $20 at HarborFreight store.

http://www.harborfreight.com/catalog...ry+load+tester

danev6972

Thanks Glyn & Pcy.

Went to Advanced Auto to get the batt checked. Dead Cell they say.
Free replacement. In 10 days the warranty expires... Got lucky.

No warranty on the new one though.

Replaced it with: Autocraft Gold Part# 49H8
Cranking Amp @ 32 Degrees F 950
Cold Cranking Amp @ 0 deg. F 760
Reserved Capacity 160

Hope it's just the batt. and nothing else...guess i'll find out later.

Carsy

No probs Dane !

bruno2009

Last August i had the same problem the battery went dead overnight and just before i was going on holiday' I had the battery checked out and was told it was u/s.
I went out and purchased a new one at a cost of £105 and everything as been all right until a few days ago, i noticed if i left the car parked up for 2 days the battery had become flat again, So i have done a few tests but after 2 days it is flat again.
This morning i decided to go to my local MB garage and said can you put yout star diagnostics on it and find the problem?
After 3 hours i received the answer it is my offside rear window motor and now the bad news to fit a new one and all the time with labour i have just had the bill for £495.00 and am well and truly pi**ed off.

Glyn M Ruck

A rear window motor - that is extremely unusual. The window motors seldom give trouble. The only common problem on early cars was the plastic bush that goes through the side window glass!!!