ok so if i understand that right the red wire from the solenoid will go to yellow wire from MSD 7531..yellow wire provides 12 volts at all times till the shift light rpm is reached and it will remove 12 volts for the solenoid to shift?? Am i correct?
No.
You need to power the solenoid through the NC terminals of a relay, and use the yellow (or brown/white) wire from the 7531 to ground the coil of the relay.
Either the yellow or brown/white provide a ground, not 12v, when activated.
Therefore,
fused +12v to terminal 86 and 30 on the relay.
Yellow or brown/white from 7531 to terminal 85 on the relay.
Power for solenoid to terminal 87A on the relay.
Solenoid ground to chassis.
This way, you'll have +12v to the solenoid, until your yellow or brown/white provides a ground to the relay, which will switch the contacts, and drop the power to the solenoid, making it perform the shift.
NOTE: You mention using the yellow wire. For a single shift operation I prefer to use the RPM/TIME switch, which is on the brown/white wire. If you are using the brown/white for something else, then when you set up your shift point, be sure to disable the 'LAUNCH LIGHT' feature, otherwise your shifter will do some funky things.
