With the original MB transistorized (TI) switchgear, current control is accomplished via coil resistance plus external resistance (~.4+1ohm). When the points are closed, the current will be approx. 8.5-9A. Avg. current with engine running approx. 3-4A.

Aftermarket systems will have about the same total primary circuit resistance, however, external resistors are not used; the resistance is internal to the coil. Peak and average current will be about the same, although there may be a a current limiting circuit in the aftermarket system.
When installing an aftermarket system, follow their instructions.