Freightliner jump starts or dead batteries with Remote Sense Alternator
I had some issues lately with Freightliners that have to be jump started several times or the batteries are dead. When performing a parasitic draw check, I find anywhere from 5 to 6 amps draw on the batteries. After pulling almost every fuse in the PDM nothing makes the parasitic draw go away. On older freightliners there is a fuse in the battery compartment and newer Freightliners the fuse is in the remote engine PDM. The fuse is for the remote sense wire, when you remove this fuse the draw goes away.
The problem is that when the tractor has recently had the alternator replaced the last truck mechanic has connected the remote sense wire to the wrong post known as the I post on the alternator. This creates a short in the alternator and pulls 5 to 6 amps out of the batteries all the time when the truck is not running. The wire must be connected to the remote sense post of the alternator. If a non-remote sense alternator is installed don’t connect the harness a non-remote sense alternator will only have 3 post on it.