I picked up a used MP P4876729 capacitive discharge ignition box yesterday. As best as I can tell this was made by MSD for Mopar and most likely is the 6ALN box.

However, I haven't really found any specific on-line information that pertains to this box. It is my first non-traditional ignition box, thought it was worth a try since I picked it up for $40.

Does anyone have any specific info on this? Can I simply use the MDS 6ALN instructions for wiring? I'm thinking "yes", but thought I'd check first before I fry anything! lol

Thanks everyone.

what does the wiring plug look like ?

Here is what it looks like...the connector itself is the Weathertight type, 6-pin that is on the 6ALN box I think. There is also a single wire connector for the Tach signal. The Red and Black wires are power wires.

I have a nicely restored engine bay wiring harness that I do not want to hack-up. So my thinking was to somehow hook-up to where the regular 4-pin ECU (chrome box in my case) hooks up and just use a couple of these wires as per the MDS wiring diagram that I found for their 6ALN box.

Once I can confirm that this MP box is in fact the MSD 6ALN I can map all this wiring out that do very little splicing I think.

Here is the factory 4-pin hookup diagram.

So the 'auto geek' in me says: "man...check this out, I could totally run the MP DC box out of the factory 4-pin wiring connector, just short of the power wires and the tach driver wire that is..."!

Yep, it's the same box. You also don't want to use the ballast resistor in the coil circuit anymore, you'd want both the black and orange lead from the MSD to go to the coil directly.

OK, good stuff.

Yup, got it re: ballast resistor. Although I do have a question regarding the box's power supply. The diagram shows a straight feed from the battery but that just seems awefully...ummm, risky?

Should there not be a fuse at least on this, or perhpas a switched power supply?

I’ve installed a few and have always gone right to the battery. They recommend not fusing it in the instructions because it is allegedly internally fused but I do know some people that have put a 20 or 30 amp fuse on the positive lead. It only draws about an amp per 1000 rpm but you also will get current spikes, especially on shutdown.

i have seen MSD boxes connected to the battery feed on the starter relay, depending on the mounting location of the box.
that may work out well if the battery cable is big enough to not have any voltage drop ?