2003 suburban - seat heater would randomly come on. It’s a common problem with the door switches on those. I don’t know if they get water in them or something but the wires didn’t chafe
?! Things do
randomly come on sometimes when they use sensors/switches that go to ground...
It doesn't have to be chafed wires. Moisture in connectors or other issues can cause it. Anything that gives a current path to the chassis prior to the sensor/switch will result in a signal sent to the module.
Please forgive me if I'm explaining things that don't need explanation; I don't know what is a common level of understanding in here. The conventional way of doing things is that a voltage supply (12V battery in automotive case) will go out from the source, through a fuse, through a switch/sensor, then to the destination (digital input on BCM in automotive case). That's how it works in your house, (mostly) in your vehicles, in appliances, and in the industrial automation circuits that I work with. Ram has decided to do it differently in this case for some reason.
Here's the diagram of the tailgate:
The BCM has a power supply inside, probably 5V or something (I'll know for sure later) and the digital input, instead of being at 0V and recognizing a transition to 5V, is sending 5V out and waiting for a transition to 0V. When you press the tailgate switch you ground out that input, pulling the voltage down to 0V and the BCM then send out power to the latches.
If using the conventional way, there is only one in a million ways that the BCM would receive the signal: if you pushed the tailgate button. Sure, theoretically, somewhere along it's path, that wire "could" somehow come in contact with a voltage source (maybe it was ran across the battery and chafed against the positive battery post?) But it is extremely
But the way ram has done it, that wire need only contact ground
. It is surrounded by ground. The entire chassis is ground. Everything that wire could possibly cut itself against, is something that will cause it to send a signal to the BCM that you want the tailgate open.
That green wire goes through 6 connectors and 5 separate harnesses between the BCM and the tailgate switch, plenty of opportunity for something to go wrong. In the reality that the cosmos has selected for you, that probably wouldn't happen. In my reality, it's worth betting on.