ok so installed an EZ wiring harness on a 73 charger with an MSD 6AL box and everything works great except it wont turn on it sounds like the power is getting cut out or something because i turn the key to start and it starts then i let it go and it returns to ON position and it turns off like if the power get cut off i connected everything correctly according to the manuals and such but im guessing the ignition wires there must be something that needs modding for it to work i just dont know what ??

 

You don't have something wired correctly One bad thing most the aftermarket wiring outfits do, is to NOT make allowances for the special way that Mopar wired their start/ ignition circuits.

It is IMPORTANT that you understand how they work

Do you have a wiring diagram for the ORIGINAL car?

Here's how the ORIGINAL ignition circuit works

Diagrams from "My Mopar:"

http://www.mymopar.com/downloads/197...etChargerA.JPG

http://www.mymopar.com/downloads/197...etChargerB.JPG

Look at diagram "B" and find the ignition switch connector. Unfortunately, those diagrams do not identify the larger from smaller gauge wires

Originally, the largest RED going to the switch connector was hot battery coming from the ammeter circuit. Must be hot at all times

In "run" TWO circuits are live, the large BLACK which feeds the switched power out to the fuse panel,

and "ignition run", sometimes called "IGN1", which is DARK BLUE

In "start" the only "live" wires are two......

YELLOW feeds to the start relay and engages the relay IF you have the clutch depressed --on stick cars with a clutch safety switch, or if the auto trans is in park or neutral. The NSS supplies a ground on the other terminal of the start relay

BROWN feeds hot battery power to the ignition during start. This BYPASSES the ballast resistor, sometimes called "ign2"

When you hook up an MSD with no ballast resistor, you MUST jumper the brown and dark blue together to get the car to start and run.

I'm guessing you did NOT run a wire out from the ignition "run" or "DARK BLUE"

 

ah man perfect, i just jumped a wire from the brown to the blue and it started right up awesome .