Electrical System Question

Some trucks/companies reduce the batteries in the battery compartment from 3 or 4 to 2 or 3 and this will surely exacerbate any voltage drain issues. And if one or more of the batteries has a bad cell that will cause the voltage shut down to occur sooner, by necessity. Or, it could be shutting down the battery accessory circuit early due to faulty voltage monitor. See if you can get the batteries checked individually, likely you have at least 1 bad battery.

 

The capacity of batteries to hold a charge, and how quickly they discharge is very different in cold weather. If you are someplace in the teens or lower, and combined with older batteries, their ability to hold a charge, and how quickly they discharge with a small load, may be much less than you think.

 

Check and make sure all your connections are tight. Sometimes just an 1/8 of a turn can make a big difference. Also any black marks or burnt anything around batteries or wiring.

 

We too have an 05 with the mbe04 its the older batteries but it is a safety shutdown to conserve battery charge we put 2 of 4 new batteries in it and you won't here the "alarm" go off so soon. and the only we leave plugged in is our 12 volt cooler when we park overnight but on hometime nothing is left plugged in. the electrical system is weak in these trucks this is not a truck that we would hard wire an inverter to, we just use a 400 watt inverter to charge phones and it willl run our laptop with the cooler plugged in plus also sit with cb on.

 

My Volvo has battery rundown but ive never heard the alarm go off, even with my Black and Decker compressor fridge running off the inverter during a 34 hour reset.

The Freightliner I used to drive would activate the alarm after about 14hrs.

 

I have on 07 freightliner with mercedes and I can't find second fuse box. Some thing is draining batteries overnight with no accessories in truck. Pulled every fuse from fenderbox but something is still drawing juice. Any suggestions would be very appreciated.

 

Is there one on the passenger side of the dash? It has a button that says "Push" and the cover flips open.