MSD is in
Thread Starter
Melting Slicks
Joined: Jul 2002
Posts: 3,128
Likes: 3
From: Deltona (son of Deland and DAYTONA) FL
MSD is in
A friend had a 6AL box and a tach drive dist and is selling to me cheap. I don't need the tach drive part, but the rest of the dist is great.
I picked up a Blaster 2 coil and 8.5 mm MSD wires to go with it, plus the looms you see in the photos.
Before I had the timing set and it wouldn't start, I tested power to the coil with the ignition on, and found none. I thought the box was defective and called MSD. They said it's normal to not have power to the coil with ignition switch on and car not running. How's the thing work then?
Still have some tie warpping to do with the wiring, but everything works.
I picked up a Blaster 2 coil and 8.5 mm MSD wires to go with it, plus the looms you see in the photos.
Before I had the timing set and it wouldn't start, I tested power to the coil with the ignition on, and found none. I thought the box was defective and called MSD. They said it's normal to not have power to the coil with ignition switch on and car not running. How's the thing work then?
Still have some tie warpping to do with the wiring, but everything works.
Burning Brakes
Joined: Nov 2004
Posts: 1,028
Likes: 0
From: San Antonio Texas
the ignition box only sends power to the coil when triggered by the distributor. there fore the distributor must be turning in order to get power to the coil. i'm going to assume you have an HEI system. as the distributor turns the magnetic trigger sends a "signal" each time a spark needs to fire a cylinder (8 times per revolution). this signal normally goes through the module and then to the coil in the cap. i'm assuming you replaced your module with the MSD harness. that harness connects the ignition box. when the box receives it's signal from the distributor it then discharges its internal capacitor (capacitive discharge ignition) and sends high voltage to the coil which then sends its stepped up voltage to the distributor cap and on to the cylinders.
the MSD manual describes a troubleshooting method for testing whether the box is working. use caution, these are very high voltage igntions systems. even though its direct current, 50,000 volts is enough to stop your heart or cause a life threatening disruption to the normal heart rhythm.
the MSD manual describes a troubleshooting method for testing whether the box is working. use caution, these are very high voltage igntions systems. even though its direct current, 50,000 volts is enough to stop your heart or cause a life threatening disruption to the normal heart rhythm.
Thread Starter
Melting Slicks
Joined: Jul 2002
Posts: 3,128
Likes: 3
From: Deltona (son of Deland and DAYTONA) FL
Grey,
I went non-hei as that's what my friend had to sell. With the blaster coil, i get comparable volts.
thanks for describing how the system works.
I went non-hei as that's what my friend had to sell. With the blaster coil, i get comparable volts.
thanks for describing how the system works.
Melting Slicks
Joined: May 2004
Posts: 2,737
Likes: 836
From: Gulf of America
2023 C7 of the Year Finalist - Unmodified
2018 C3 of Year Finalist
If you didn't get the paperwork with the box. just a word of caution. Don't hook up your 30 year old Sears tach/dwell meter to the coil to get your rpm readings when setting the idle on your carb. Don't ask me how I know. 
The 6Al box will have a tach port off the side of the box for tach readings. Even sez so in the instructions! 
The 6Al box will have a tach port off the side of the box for tach readings. Even sez so in the instructions!
