2016 Pete 389 interior/cecu problems

[Rawze]

Pete and kw (paccar) cecu's are notoriously flaky. Disconnecting ALL batteries and power sources to the truck for 30 minutes + so that the residual power and memory on the circuit boards in them finally dies will hard reset them and cure many ailments they get themselves caught up into.. Dash gauge lights not operating as intended, speedo sometimes acting up, and a lot more ghost problems. It is a well known issue that has been around for years now and also has been discussed on here many times in the past. You would think that by now every damnned stealers%$it and repair shop in the usa should know this .. yet they all seem to have some kind of amnesia when it comes to this issue.


Unlike older trucks and cars of yester-year ... The cab and chassis grounds are not used by the electrical system at all on all modern trucks ... The fact that it has some electrical noise in it is mostly meaningless outside of ensururing they are grounded properly. Just ensure some moron did not connect a gauge, device, or other thing that did not come with the truck from the factory to the chassis to get a ground... ALL grounds should come from the wiring harness alone and none of them should reference or draw current off any of the metal surfaces of the cab, chassis, etc.

The chassis and cab and other things do have a ground wire going to them to prevent static voltage buildup, etc. but that is their only purpose. Nothing should be connected so that it draws (negative voltage feed) and be power by it though.


If some moron hooked up a CB-radio or e-log device and tied the negative wire to the chassis somewhere instead of the grounds in the wiring harness, this could be some issue... or in the extreme case, for all anyone knows, the used truck stealers$it or someone else could have installed a GPS tracking device hidden way up into the dash of the truck to track it and sell the information online or to track it in case you decide not to make truck payments... and they could have tied the ground wire to the chassis like a fool.... i cannot tell you how many dozens of hidden tracking devices I have found inside people's trucks that have come over here to visit... who had no clue that someone had installed one into the truck before they purchased it... many of which are wired up half-arsed like this.

Lastly, as far as measuring slight voltage differences on the chassis ... most digital modern volt meters are notoriously bad at picking up static garbage (like a radio antenna would) when connected to large metal surfaces vs. an old analog type of meter...use an old style analog style of volt meter when you think you are chasing electrical noise to eliminate the static differences the large metal surfaces might be imposing on a digital meter.