2016 peterbilt 579 paccar motor

Easiest way to find out what is grounding is to pull each fuse and touch a current sensor to the slots. If you have power goimg through without a fuse then just backtrack that. As for a wireong diagram good luck. The one for my 2017 579 is a....suggestion at best. Half the #### wires arent attached where they should be due to being spliced so many times.

 

On the firewall where all those electrical harnesses are....follow the wires down and they should be tied up to a piece that sticks out from the frame. Cut them loose, unwrap the bundles, and start looking for wires that have rubbed thru. Just had to do this last week on my 2017 579 and found 8 separate wires in various stages of no longer being in one piece.

 

Trade it.

 

Also, when you tie the bundles back up you can wrap a CAC boot around the bundle to keep them from rubbing on the metal piece they’re tied to.

 

If that wasn’t your problem then start looking at places like this where they have stuff bundled together from the factory. Cut them loose and start unwrapping everything and checking for where wires have rubbed together.

 

Look into one of these. If your on the road, you can clear your codes and get you back home or close to a shop. It could fix the bugs in the ECM or at least a temporary patch.

 

I bought mine directly from OTR, on eBay it’s costs an extra $50. It’s cheap insurance and will pay off itself off on its first use(a tow). Mine has paid off itself several times already. One of the contractors I haul for has one on each truck with a Paccar engine, (they have 3 left and are getting rid of them one by one). I have a Cummins engine and only bought it for insurance and like I mentioned, money well spent.