Ignition problem

[Gargemel78]

I recently decided I would do away with 3/4 of the old factory wiring and just use a MSD box. I was going to run the field alternateor off the blue ignition 1 wire and the MSD off The ignition 2 brown wire. I have the ignition switch just laying bare in the car (no column) and am able to test the lugs in the back I have constant power to the red and black wire and switched power to the yellow but nothing to the brown ignition 2 wire. What could be the possible cause a safety switch maybe l?

 

[Gargemel78]

Wiring

 

[Nacho-RT74]

Ign 1 ( Run ) and ign 2 ( Start ) have power on diff stages of the ign switch. Both are hot just when the ballast resistor is present since both reach the resistor, at diff levels on every stage but both hot. If you removed the ballast resistor you missed that.

If you looked at your cluster with detail, when cranking the engine with original wiring, the brake pilot light on cluster ( oil too if standard cluster ) dimmed while cranking and was firm light on while in run. Thats because the brake light in cluster gets the power from run circuit ( ign 1 ). When cranking, the switch changes te feed to ign 2 ( brown ) to full feed the coil for a faster start up, but Run circuit remains hot through the ballast, with a decayed voltage but still hot. Thats the same it happens while car is un RUN, but to the Brown circuit to keep safe the coil from unnecessary high voltage

HOWEVER, if you are testing the ign switch directly and you are not getting voltage on brown wire while cranking, then there is a fail on ign switch.

Red comes from batt/alt circuit
Black is acc ( just in run )
Blue is ign1 ( just in run, but getting lower voltage in while cranking as far ballast is there from it )
Brown is ign2 ( just while cranking to bypass the ballast to coil, but also hot with lower voltage while car is in run, as explained above )
Yellow is starter motor relay trigger ( just while cranking )

 

[Nacho-RT74]

MSD box can work with the ballast still on car, getting the remote on signal from the coil + lead wire, no matter the voltage decay, since the voltage coming from ballast is still enough to keep on the MSD box. The MSD box gets the power source from the thick red wire what commonly is sourced from batt.

Normally ppl removes the ballast and splice all those wires together to keep same voltage rate to MSD box in both stages, but is not really necesary, and MSD sheet instructions diagrams states the coil wire can be used without say remove the ballast is a must.

Remove or modify the ballast is mandatory when using the RTR distributors, since that wire is also the one what feeds the ign system internally on RTR dist, and not just the remote on signal