Quick question. What is the polarity of the magnetic pickup for an HEI? I have one with a light green wire (plugs into the G marked on the module) and a light tan wire (plugs into the W marked on the module).

I'm adding an MSD and they list a polarity for there magnetic pickup.

Thanks

 

Not sure but your MSD should have come with connectors specifically designed to plug into an HEI pickup. They are keyed to only fit on one way, doign away with questions about polarity.

 

I bought an MSD box at a local swap meet for $5. Hooked it up to the HEI per MSD directions and it worked perfect.

I attached the pickup to the MSD box and guessed polarity. It worked fine. I reversed the polarity from the pickup to the MSD box and again it worked fine.

I'm sure there is a preferred polarity for the HEI.

 

Well there shouldn't be. Because we have a coil that picks up currents induced by the spinning magnets on the shaft. It's an AC signal, so polarity is not an issue.

 

Goto page 7 of this document.

MSD info