Hello,
Here's the story...for the past couple of days I've noticed that my battery is starting to go. When I start my car in the morning it has that slow feel to it. No problem, I'll replace it on the weekend, right? Well, today I started my car and drove it to the coffee place near my job and turned it off while I got my morning coffee. Five minutes later I went out to start the car and drive the one block from the cafe to work, but it wouldn't start. The battery, it seemed had met its maker. I walked to work and decided to get a jump from someone at work when I leave for the day. So a friend from work drove with me to my car and I decided to give it one more try...no luck though. He helped me push the car out of its parking spot so that we could use his car for a jump. At that point I tried one last time, and somehow my car started! Great, I'll drive home and get a new battery tomorrow! As soon as the idle dropped down to the normal level the "bulb out" light lit. I had not yet turned on my lights and if I remember correctly, the bulb out indicator only works on lights that are on at the time. I turned on my lights and inspected all of the exterior lights including the license plate lights and the turn signals, everything is on and looking good.

Boy, this one is too long! Sorry. Anyway, any ideas what might be the problem, or where to start looking? My car is a 1987 560SEL

Thanks!

OF course that system also monitors the BRAKE lights...CARS hate jump starts!

IF you really need to JUMP start a car....connect the cables & wait at least 5 minutes with the other car charging YOUR battery...then shut off the engine & try to start your car ...WHEN your car does start leave the jumper connected for another minute or 2. That will help with voltage SPIKES!

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Thanks for the reply. I think that you might have misunderstood me, I started my car normally, without the aid of my friend's battery.

Low battery voltage can/may sometimes cause electrial problems. (M.B. Doc, good info about the jump start). Your car started after sitting for a while: sounds like a battery, do you have the white Mercedes battery in you vehicle?

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www.theworkshopmercedesbenz.com
Nahum:1.7

Why did the battery die? I wonder if your alternator is not putting out enough voltage, or if the battery is so bad that it's holding the voltage down (this problem will not last...)

A completely dead battery doesn't smooth out the spikes from the alternator very well, if at all. I would heed the above caution.

__________________
86 560SL
With homebrew first gear start!
85 380SL
Daily Driver Project

http://juliepalooza.8m.com/sl/mercedes.htm

Fortunately. MBZ alternators have lots of cooling and seldom overheat or fail. It is part of the DIN testing required to get certified in Germany. All the 'accessories' have to be able to run at full load at any speed--from slowest idle to maximum RPM/road speed indefinitely in any climate condition for which the car is certified.

However, a 'dead' batery does place an extraordinary load on the alternator as it tries to recharge the dead beast. Batteries fail from slow aging (lead oxide and lead sulphate flake off the plates, fall to the bottom, eventually leaving no active surface or shorting out at the bottom.)

Low voltage will cause a host of weird symptoms.

The alternators seem to be built very well, but I had to replace two regulators on two alternators with brushes on their last legs. I don't consider this to be a "design failure", just a wear item.

__________________
86 560SL
With homebrew first gear start!
85 380SL
Daily Driver Project

http://juliepalooza.8m.com/sl/mercedes.htm

The battery is not a "Mercedes" battery, I forget who it is from. It was in the car when I bought it 6 years ago. How long should a battery typically last? Before buying this car I never held on to a car for more than a year, so I never really thought about the battery. Either way, I am picking up a new one tomorrow morning.

Six years on that battery - it owes you nothing more. I bet all is well once you put a new battery in there.

Len

Well, the new battery is in and all seems well. I sigh of relief has been...sighed.

Thanks everyone for your replies!
Justin