First of all, thank you for responding to my inquiry!
Does your tach have a gang connector with all the wires going into a single connector, or individual connectors for each wire?
I crawled underneath the dash (tough when you're 6'3"
) and I noticed one connector with (I think) four wires going into the back of the tach. EDIT: SPF #747 was built in late '99 or early '00.
The previous owner connected the MSD box by using the dedicated tach output port from the box and splicing in one wire from the SPF harness to that port. No tach problems until I disconnected the box and reinstalled.
I called MSD support this morning and they said that many SPF owners have experienced intermittent tach problems when using an MSD box and that I should insert their PN8920 Tach Adapter. So I just made Jeg's $50 richer....
Is my SPF tach voltage triggered or current triggered? The
current triggered wiring instructions from MSD are easier.
Thanks! Drove to Newport Beach yesterday, then up to Huntington Beach, then past Knott's and back to North Orange County. It totally sucked not having a tach working!