raise your hand if you like dodge wiring

Resistance (when used correctly) can change voltage.  Voltage can be precisely monitored to allow more then one function to be transmitted on a line.

I believe it was BMW that first started using multiplexing in vehicles, but in the end it saves a lot of weight and cost.  If you are having issues with simple multiplex systems stay away from CAN and LIN busses!

The best way to troubleshoot a problem like that is to first determine what controls those lights.  Next, you have to figure out what, under normal circumstances, would turn those lights on.  Lastly, you figure out what has changed.

I realize that this is a very simplistic approach, but if you can figure out each of these things you'll at least know where to start looking.

The other CAN /LIN system advantage is that it offers built in diagnostic ability, apart from the weight and cost saving, chips are cheaper than copper wire.

Come to think of it, KP was almost right , BMW used it on the secondary lock control from 98, Mercedes from about 95 on the locks and the good old Ford Probe from who knows when.  Did I call a Probe good?  What a nasty car.

Yes, basic troubleshooting rules.

You would be better off to do a google search for the busses, but from memory the basics are:

CAN bus - two wire high speed system where there is no master controlling communication.  Any module on the bus can send a message to any (or all) module at any given time, assuming the bus is clear.  There is a system in place to request and arbitrate which module has control of the bus.

LIN bus - one wire low speed system where the master must start all communications.  This was designed to be a "low cost" bus and typically is used on non critical tasks, like body control stuff .

Both systems transmit serial data on the bus.  CAN busses are cool because they can detect wiring faults and if a wire is damaged the bus will automatically switch to a reduced speed one wire bus to keep things running.

There is obviously, much, much more to them then this, this is just a basic outline.