MSD Tech: Ignition Troubleshooting

10 min read

MSD Tech: Ignition Troubleshooting

10 min read

Power Wires

There are two heavier gauge wires on the MSD, a Red and Black. The heavy red wire needs to be connected to the positive side of the battery. Connecting it to the battery side of the starter solenoid is also okay, but the directly to the battery positive terminal is ideal.

Next, confirm that the heavy black wire is connected to the negative side of the battery, or directly to engine ground on the head or block.

Locate the small red wire coming from the MSD Ignition. This wire turns the MSD on and off, so make sure it is connected to a switched 12-volt source. Use a test light or volt meter to confirm that there is 12 volts on this wire when the key is in the On position – as well as during cranking. It is important to check for voltage during cranking as in many cases a wire may show 12 volts with the key on, but will drop during cranking.

Next, lets review the coil wiring. The ONLY two wires that should be connected to the coil are from the MSD. The orange wire connects to coil positive while the black wire connects to the negative terminal. No other wires should be connected to the coil terminals! Also, do not touch or connect any tools to the coil. With the MSD connected there will NOT be voltage on the coil terminals unless the engine is running – and in that case there will be over 450 volts due to the CD technology of the ignition. Again, the only two wires connected to the coil are the MSD Orange, positive, and the MSD Black, negative.

We’ll move on to the trigger sources. There are two trigger inputs on the MSD; a White wire and a 2-pin connector with a Violet wire and a Green wire. These are the wires for the incoming trigger signal from the distributor. It is important to note that only one method will be used, meaning either the white wire is used, or the 2-pin connector is used. Both will never be connected at the same time.

Lets start with the White wire. The White wire is used to connect to breaker points, amplifiers or other electronic pickups. The white wire connects to the original coil negative wire. This wire is not used if you have an MSD Pro-Billet Distributor with a 2-pin connector.

2-Pin Magnetic Pickup Connector

This connector plugs directly into the matching connector on an MSD Pro-Billet Distributor. This is called the magnetic pickup connector. When it is used, the White wire should be sealed and not used.

Note that there some MSD Distributors that have a three wire connector. These are called Ready-to-Run Distributors and do not require an MSD Ignition Control.

That completes our wiring check of the MSD 6-Series Ignition Controls. Be sure to check for a good ground connection. Also, if any wires were cut, confirm that quality terminals and crimps have been used.


Ray Frescas
135 Posts