In your case you should only need one splice for the orange wire and one for the yellow. Then you need the splice for the grounds from the doors and the 4wd light.
As for how many, I've seen factory line splice runs with 5-6 in them. Far more than I would do though.
The problem becomes the amount of current the single run can handle. That's why they used the chassis for ground a lot. The chassis is a big hunk of conductive metal so you could ground everything to it. Then when computer controls started becoming very sensitive it was discovered that the chassis ground didn't work very well for the sensors. There was too much voltage drop through the steel to make them reliable. That's why newer cars have hundreds for circuits, every little item has it's own power and ground.
Jan 16, 2017 at 4:35 AM