It's going in a 91 rex sohc motor.......... the white wire indicates it should be connected to points or amplifier output (connects to yellow wire of timing accessories) at least thats what it says on the back of the unit. The other is a plug indicating it's a magnetic pickup in distributor or cranktrigger. It states that you have to connect one of them but not both of them at the same time......... any clue on what this means? TIA