ekalb

I just went out to the car and got absolutely no response from it. I had to use the actual little key to get inside it. I hooked up a charger and was able to get it running after about 15 minutes of letting it build up some juice. I drove it around my neighborhood for a few minutes and then shut it off and was able to restart it normally right away.

So after searching here it looks like it could be:

A. Batteries (both)
B. Voltage regulator
C. Alternator


The car does not get used often at all. It probably has not been started since last friday, but there was absolutely no warning of this coming (aux battery warning on the dash etc).


Any idea what I should be looking for first? Obviously, the voltage regulator would be the cheapest fix, but I don't just want to throw money at issues that may not fix it. I have not replaced the Main or Aux battery in the two years I have had the car.

Ders

You can check the voltage through the console. This shows the voltage of the main battery/voltage regulator I believe. Check this video out:

ekalb

Right, I forgot to post that. thanks for the link


12.4 not running
13.4 while running

It hovers between 13.4 and 13.5 running.

JoeJErnst

It's probably your main battery. Make sure you don't have a dome light on, or anything else that would cause a slow drain while the car is parked. Take it somewhere where they can test your battery.

ekalb

Would a shop have a more in depth way of testing it than my multimeter?

Does it make any sense to replace the AUX at the same time. Maybe I can make it a daylight savings thing along with the 9volts in my smoke detectors lol

Rocman8

Check the date codes on both batteries. The main one is usually stamped on the negative post.

JoeJErnst

Yes, most places that sell batteries have a little cart they can hook up to the battery and run some diagnostic tests. I don't know exactly what they do, or how well our fancy-pants MB electronic systems would behave, but you can certainly take your battery out of the car and tote it down to Napa and have them run a test on it.

ekalb

Ok, thanks!



I had the car running for another 15 minutes or so and then shut it off. Upon restart, i am now seeing this error:




The passenger side headlight is apparently "dipped" and it will not turn on. It was absolutely running fine when was running them earlier today. I have tried a few restarts since and it will not fix itself.

I have an appointment at MB tomorrow at 8am to get this all looked at as well as a few other small issues I have ignored.


thanks

ekalb

I just ran DAS on it and found a "Battery Control Module" error.


Is that a software type fix or is it hardware that needs to be replaced? Just trying to get an idea for what MB will tell me tomorrow.

cetialpha5

Should be closer to 14 when running although 13.5 is fine if it's just at idle. You can drive it with the voltage display on and see if it goes higher once you're driving it. You're in MA so if you end up getting a new battery, probably Advance Auto has the best price, they usually have some 30% off coupon code on retailmenot.com that will take $50 off the price of the battery. They also install for free. You can take it to them to get it load tested. Otherwise if your voltage display isn't going up more than 13.5, then it's either the alternator or the battery control module.

bbirdwell

Solar BA-5 battery tester. When my batteries test at 50% of rated CA or CCA, I pull them and replace with new. Nice-to-have tool.

Forrest Gump 9

Yep, good old Battery Control Module. I used to have the same problem and thought it was my battery but after replace that BCM, no more problems

cetialpha5

It's a piece of hardware. How much did they say it was?