What you are describing is probably the electronic ignition module, which goes between the distributor magnetic pickup and the ignition coil to produce the high voltage for the spark plugs. It has a four pin connector and a transistor on it.
Does it look like this ignition module? : https://www.summitracing.com/parts/dcc-4120505
If so, this module is not the voltage regulator for the alternator (which does charge the battery(s) on the van). The part in the link in the previous message from Bruceper is the voltage regulator, which has a two pin connector on it.
What makes you think you need to replace the voltage regulator?