Question Regarding Ignition and Alternator Wiring

I just finished installing an MSD 6 ignition box for my 304. It fired right up, but my alternator warning light stayed on, and my voltmeter was reading below 10v.

Here is the diagram to wiring the box to the stock points setup, which is what I did:


Notice the small red wire is to hook to the original coil positive wire. In my case, that was the pink resistor wire, which I assume is the same as a ballast resistor on some models, and the MSD instructions say it is not necessary. So, I ran a new wire from the same spot on the key switch to tie into the small red wire to turn on/off the MSD.

So, that bypassed the resistor wire, and it also did away with the wire that went from the coil positive to the solenoid "I" post (C-42). I disconnected those wires. The only wire now hooked to the solenoid "I" terminal is the yellow wire (C-40) going to the voltage regulator.


Should I have run a new wire from the key switch to the solenoid "I" terminal, and then hooked the MSD 12v small red wire to the same solenoid terminal?

My only other head scratcher was the diode installed on C-6 from the voltage regulator to the dash warning light to prevent engine run-on.

 

The C-42 wire which you removed is likely the power wire that feeds C-40 to the regulator to turn it on and tells the alternator to charge. This is why your chrg light is "ON" as the alternator is not putting out any power hence the 10V reading.

 

Yes. On those starter solenoids, the ignition terminal (I) is only energized when the key is turned to start. With the key at run, that post is only connected to itself, serving as a junction between C-42 and C-40. Leave the resistance wire and C-42 in place, and simply remove the connection to the ignition coil but leave them connected together. Then get your 12V for the MSD unit back at the origin of the resistance wire.

 

Thanks to both of you. That confirms I was somewhat thinking correctly. I simply disconnected those wires and taped up the ends. Reconnecting them will be no big deal. I'll have to tie the wires back together under the dash at the switch where I spliced in the wire to bypass the resistance wire.

Why does the resistance wire stop at the firewall and its a regular wire from the firewall to the switch? For splicing or tapping for things like this?

 

The resistant wire is a resistive measurement in ohms by the type of wire and it's length, correlated to the design of the coil. Many special resistance wires are approx 3 foot in length.

 

That took care of it. Purrs like a kitten and charges like a bull. Thanks.