Just wondering how to wire the MSD 6A box up to my motor? Its currently on my buddys 90 IROC-Z. Is there a different wiring harness Ill need to buy for my motor or can i just wire it myself. Please help. THanks

 

The thicker black wire get's grounded to the chassis, the thicker red wire get's hooked to the positive side of the battery....


The thin black wire get's hooked to the negative side of you're HEI cap (or coil), and the thin orange wire gets hooked to the positive side of the HEI cap (or coil). There's a seperate ground wire that gets plugged in between the two, and then get's grounded on the firewall.... just use the existing groundstrap location from the engine to the firewall (firewall side of course)....


The thin red wire coming from the box (it should have a small white jumper at the end of it) gets wired DIRECTLY into you're ignition wire (the one that originally got clipped into the HEI cap on the positive side)....


You're original RPM wire now get's rewired on the left side of the MSD box itself (you'll have to crimp a new terminal on the wire for it to plug in)...