Proper Battery Wiring Configuration

The simple thing would be to go to your freightliner and ask them. Take your photo and a mechanic would know.

 

Ok, in your picture, the two white wires with some red on them are actually ECM power wires. The 3rd white wire is the ECM ground. If that cable was smoking then you must have missed installing the main ground cables and the everything was trying to ground through that. Or the eyelet had a bad connection at the stud. You should have two main ground cables going to the batteries. You have the front two batteries connected properly to each other, but they still need another connection to the truck somehow. Same thing with the rear pair. I can see the ground cable at the bottom of the picture. When you put the all the cables on make sure they all sit nice and flat and flush with each other and don't have any bad gaps where they over lap. You are almost there!

 

sorry if i may have caused some confusion about the other ground cable, from the angle of this photo the other ground cable cant be seen. it is disconnected and laying next to the battery (battery closest to the front of the truck)

ecm white wires, yes there are 2 white wires (positive) with red shrink wrap on them and 1 white wire (negative) with black shrink wrap on it. should the negative ecm wire be connected to the negative battery post or to the frame? (really glad to know what these white wires are for)

 

Always to the battery. The frame from corrosion to paint to oxidation doesnt really make a good ground.

 

Yes, to the battery. Sounds like your problem is just bad connections. Those Freightliner style battery to battery jumper cables can get pretty nasty with corrosion under the plastic, very hard to clean.

 

I can't post a discussion on this website but I can reply to posts. I started reading this post about how to connect a battery because my apu unit drains the batteries at night it is a thermo king unit with 19200 hrs on it. If u connect a multimeter to the batteries while it is running then u can see the voltage go up so u would think that the batteries are being charged. However I wake up to the low battery alert beep when I run it so I'm just idling for now. I think the problem may be in the battery box, there is a black cable in there that isn't hooked to anything my mechanic said it is a.spare but I would like to know.if this could be the ground for the apu. Comments are appreciated, thanks.

 

You need to check the output of the APU alternator. It may be putting out battery voltage but might only be outputting a few amps. If your current draw is larger than the alternator can sustain, your batteries will go dead.

You can buy a multimeter that has an inductive clamp for checking current from Lowes or Home Depot. Make sure to get the one that says it does DC current.

 

Hi guys need help i replace Volvo d13 battery after that I’m getting j1939 and j1908 please help