Help me ID this please.

AJ/FormS said

Our cars have two ignition circuits going from the ignition system; One from the start position and another from the crank position. For aftermarket ignition systems, these two have to somehow be joined together.
The cheap-O way is to run the blue wire and the brown wire together. But this leaves the start relay energized and sometimes the starter won't shut off.
The better way is to run the poweramp off the run circuit and relay the brown wire to send 12 volts to it whenever she's in crank mode.
This should be detailed in the MSD instruction manual.
Since the MSD only uses these signals to turn on the amp, there is very little current draw thru the relay, so it only has to be reliable. The amp has it's own battery power-supply.

OOPs I think I answered a non-existent question,lol.

Click to expand...

Uh the above should not be true. The brown bypass circuit is a separate key contact from the yellow start circuit

So far as the op, whatever that wiring is, should not be connected to the MSD run circuit

As said it is VERY likely the seat belt interlock. Does it have a reset button on the other side? The looped bypass is there to bypass the device and that should be your "start" circuit to the starter relay. has nothing to do with "run."

the normal way to hook an MSD is to connect the "small red" which is essentially a "trigger" wire to the original "run" circuit, with the brown bypass jumpered to it. IN FACT you can even leave the original ballast resistor in there, and simply connect the "small red" to the original coil+ wire as long as the bypass wiring is intact

HOW THIS WORKS

You have two circuits feeding the coil/ ballast, originally. IGN1 "run" is ONLY HOT with the key in "run." During start, it goes dead

During start, there are TWO ignition switch contacts "hot." One is the yellow "start" wire going to the start relay, t he other is the brown which bypasses the coil resistor. It originally connected to the coil+ side of the ballast resistor