New Battery - DEAD - Car won't turn, slowly getting discouraged...

[AlexHart]

Hi all,

I bought my first w123 (300CD) in October '09 and put a new battery in when I bought it. I changed glow-plugs as well recently. I left the car out on the street over the Holidays for about 12 days and traveled back home to see the family. The car wasn't started at all and sat in cold, New York weather (10 - 30F).

I got back last night and tried starting her up. Battery was very weak. The glow-plug light wouldn't come on. The only lights that were lighting on the dash were the battery light and the seat-belt light. Of course, it wouldn't crank at all.

I tried jumping the car. I connected cables and let the car sit for a few minutes. The glow-plug light on the Merc started to light up properly. It felt like it had juice, but I guess it wasn't enough. When I hit the switch, it cranked very slowly. I could actually hear the crank moving. Didn't start. It feels like there's not enough juice to get her going.

I know that the battery may become weak in cold weather, but the battery is almost brand new. Would the car drain the battery just sitting there?

Is this a battery issue or is this something more involved? I assume it's the battery because the lights started working as soon as I used the jumper cables.

I'm getting discouraged about the car. I was expecting so much from it and it keeps leaving me stranded.

Thanks in advance.

[Graplr]

You did not charge the battery enough. This is why it didn't fire after you tried to jump start it.

With no charge in the battery after sitting there are only a couple options that could have caused it-

1-Bad battery. Probably not it since the battery is new, but sometimes a new battery goes bad quickly.
2-Charging issue. Bad alternator,voltage regulator, wiring.
3-A drain on the battery. Meaning something is pulling volts from the battery (like a dome light, etc.) while it is sitting turned off.


When you try and jump start a dead battery diesel you need to wait awhile (much longer than a minute or two) and give it a FULL glow cycle which is about 30 seconds or perhaps even 2 full glow cycles.

To get it started you should either let a car charge the battery for 10 plus minutes or greater before trying to jump it or hook up a battery charger to it. You can take the battery out and charge it inside the house.

[1985300d]

on the passenger side under the hood,

there is a little black box like object on top of the wheel well with wires going in it, between the battery and the antifreeze resivor

make sure all the connections are all clean

[johninva]

I've never had any luck jumping any of my Mercedes diesels, alwAys had to swap batteries. Bring the battery back to where you bought it, let them test it maybe it's bad

[Graplr]

Originally Posted by johninva

I've never had any luck jumping any of my Mercedes diesels, alwAys had to swap batteries. Bring the battery back to where you bought it, let them test it maybe it's bad

I have been able to jump mine, it just needs to sit for awhile before I try and start it. I let the car charge the battery for at least 10 minutes before I try and start it.

[colincoon]

I have a drain in my car somewhere too, after sitting for a few days the battery will go dead.

I have a wall charger that I just hook up for 30 minutes when this happens, and immediately start the car after disconnecting it. Usually it has enough juice to start normally. 10 minute drive later and all is well again.

[AlexHart]

Thanks, all. I bought the battery from a BatteriesPlus in Georgia, where I purchased the car. There aren't any BatteriesPlus in New York so taking it back isn't an option. I'll try jumping again, waiting longer than a few minutes. I did try to jump it a second time. I waited close to 5 minutes on that attempt, but still didn't turn.

The issue may be a drain. I have an aftermarket radio that may be causing it. Also, there was some battery fluid (very little) on top of the battery. Maybe it is bad, who knows, I might just push it to the shop and let them deal with it.

I also just noticed a huge puddle of oil underneath the car. It has never leaked oil before. I guess I can't let this sing sit for a few days ever again. Bad way to start 2010.

[Graplr]

Originally Posted by AlexHart

I guess I can't let this sing sit for a few days ever again. Bad way to start 2010.

The first winter with an old diesel is a learning curve for everyone. I was about ready to throw in the towel on mine after the first winter but I kept with it and now know how to better prepare.

[AlexHart]

Originally Posted by Graplr

The first winter with an old diesel is a learning curve for everyone. I was about ready to throw in the towel on mine after the first winter but I kept with it and now know how to better prepare.

I hope you're right. I'll keep at it. I just don't get how a brand new battery can drain so easy. My Mustang has been sitting for months in the garage and it starts right up every time.

[Graplr]

Originally Posted by AlexHart

I hope you're right. I'll keep at it. I just don't get how a brand new battery can drain so easy. My Mustang has been sitting for months in the garage and it starts right up every time.

It may be a NO CHARGE issue (see #2 in my original post on this thread). But small drains only take a fews days to make the battery weak enough to not start in these diesels. Diesels need more power to start than a gasser and it takes heat to start a diesel (glow plugs which take power to use). Generally speaking, the little things affect diesels more than gassers in not starting.

[AlexHart]

Originally Posted by Graplr

It may be a NO CHARGE issue (see #2 in my original post on this thread). But small drains only take a fews days to make the battery weak enough to not start in these diesels. Diesels need more power to start than a gasser and it takes heat to start a diesel (glow plugs which take power to use). Generally speaking, the little things affect diesels more than gassers in not starting.

Thanks for all the info. I was thinking that it would most likely not be a no charge issue since the car was working/starting fine for a few months up until I left it sitting without starting it for a few weeks.

[Graplr]

Originally Posted by AlexHart

Thanks for all the info. I was thinking that it would most likely not be a no charge issue since the car was working/starting fine for a few months up until I left it sitting without starting it for a few weeks.

The cold amplifies every problem. Your train of thought is most likely correct on the issues. However, it does not rule out the possibility of a charging issue.

[Crazy_Nate]

If you disconnect / reconnect the negative terminal on the battery, is there a large spark?

If so, you might have to try troubleshooting your drain by pulling fuses and seeing if it lessens or goes away (a multimeter will help greatly).

[AlexHart]

Originally Posted by Crazy_Nate

If you disconnect / reconnect the negative terminal on the battery, is there a large spark?

If so, you might have to try troubleshooting your drain by pulling fuses and seeing if it lessens or goes away (a multimeter will help greatly).

Thanks. I know I need to get the drain issue sorted out. But why does it matter whether there's a spark or not? Either way, I have to figure out what's causing the drain, correct?

[Graplr]

Originally Posted by AlexHart

Thanks. I know I need to get the drain issue sorted out. But why does it matter whether there's a spark or not? Either way, I have to figure out what's causing the drain, correct?

The spark shows that there is something causing excessive drain. If there is not an arc then all is well...or something like that.