Hi there,

The heave cable to the starter motor is Pos(+) the small wire is solenoid switching power, active only when key is turned to start. The starter is earthed to the engine, which has a main earth cable attached to Battery and chassis. If there is an earth cable at the starter, it will go to the battery neg (-)
If in doubt the battery Neg is always the smaller of the two battery terminals and will be marked as (-) or Neg this can be attached to the starter mounting bolt. NOT THE SOLINOID TERMINAL

Mark (mhpautos)

Answered by mhpautos (expert)
26,869 answers provided