MSD 6A box ignition wire problem

[422cuda]

I am installing a MSD 6A ignition box and am having a problem finding a power source to splice the boxes ignition power wire into. Everywhere that has power with the key in the "on" position, loses power when I crank the engine over. I read that you can splice the two wires for the ballast resistor, but that loses power also when you crank the engine over. Called MSD and they were no help! They told me to run it down to the starter solenoid, but that loses power when the key is in the "on" position. Can anyone help me with this problem.?

 

[67Dart273]

No, you were on the right track originally

(First, what are we working on here, year, make, model?)

Let's say you have an older "points" car. The easy way is to take the MSD "trigger wire" (the one they tell you to hook to switched ignition)

Hook that to the ORIGINAL wire which went to your coil+

Hook the two original ballast resistor connections together

ORIGINALLY, here is what happens

There are THREE separate switches in the ignition switch "can" which has to do with start and run

YELLOW goes from the switch, through the bulkhead, to the starter relay, hot only in start, and causes the relay to fire and crank the engine when the start relay "sees a ground" in park/ neutral

DARK BLUE is "ignition run" or "IGN 1" and is hot ONLY in "run." It goes COLD during "start."

This is originall hooked to the "switch" side of the ballast resistor, the coil being hooked to the "coil" side

BROWN is "bypass" or "IGN 2" and is hot ONLY in start but is SEPARATE from the relay or solenoid. It feeds hot power to the coil+ during crank, and IS THE WIRE you need to HOOK TO THE BLUE (connecting the ballast wires together does this) and this wire is what you need for start

DO NOT hook to the start relay "yellow" OR the starter solenoid. Both of these will cause a "backfeed" condition when running.

You MUST check the "brown" for power during "start" BY USING THE KEY and NOT by jumpering the start relay.

IF the brown does not seem to be working, you have several choices

1 "Fix" the brown. It's either a broken wire connection, a bad bulkhead connector, or the ignition switch or switch connector.

2 You can install a later "Jeep" start relay like this one, which has an auxiliary contact for that purpose, labled "bal" for ballast

3 You could parallel a separate Bosch style relay, fired by the start relay to supply this circuit

4 You could install a good heavy diode from the start relay sol. connection (the "square screw") to the MSD "run" buss. The band on the diode needs to be on the end hooked to the ignition, and you can buy these at Radio Sh##.

 

[422cuda]

Thanks for all info! I appreciate it a lot and will let you know the results. I'll try it out when I get home. I am working on a 1972 Plymouth Barracuda with a 340. I ameunning the MSD distributor, 6A box, and blaster 2 coil on it.

 

[70aarcuda]

check the wires where your ballast resistor WAS....brown and blue....splice those wires together and hook it to the red msd wire..

 

[srduster340]

I just installed my MSD box and the instructions do not include a ballast resistor. But then again I do have a MSD distributor. I have attached an MSD instruction page.

 

[67Dart273]

We're talking about what to do with the wires that "were" on the original ballast, but thanks for the destructions post.

 

[srduster340]

Ok. My bad. ops: