Starting problem

[GOTMACH 10]

Just finished installing my Ford Racing 427 Cobra crate motor. Added the MSD 6AL box, blaster coil, and tach adaptor. Went to start it up for the first time and would turn over but not fire up.. Hooked up my hand starter switch at the solenoid and started just fine. Put the terminal back on the solenoid and tried to start with the key again and it wont fire up? Can start it with the hand starter only?

[Wycked69 20]

If it starts and runs when energized at the solenoid with the hand starter switch but not when the key is used to start it, My first guess would be it sounds to me as if you getting voltage to the coil with the key in the run position but not when its in the start position. I've not wired in an MSD with a 6AL box so I cant advise what was disrupted when installing the MSD components.

[GOTMACH 10]

I think your on to something there but I'm not sure what..

[1969_Mach1 333]

I don't recall the exact color codes.  But the MSD box needs one constant 12V source usually attached to the starter solenoid at the + battery cable stud, and one switched 12V source that has 12V when cranking and in the run position.  I went directly to the ignition switch for that.  The MSD box attaches to both the + and - coil terminals and the distributor.  The original + wire to the coil does not and cannot be used because it has a resistor wire in the circuit.

 

I am guessing the switched 12V wire to the MSD box does not have power while cranking.  When you use the remote starter button on the solenoid you have your ignition switch in the run position supplying the 12V to the switched 12V wire to the MSD box.  Does that make sense?

[GOTMACH 10]

Thanks guys, you were right. I wired the small red off the MSD box to an accessory 12v power source instead of a switched power source. I didn't realize that the ignition switch does not give power to accessory in the start position. Really appreciate your help!

[1969_Mach1 333]

Great news!  Once in a while I am on the right track with everybody else.

[JXL 12]

I don't recall the exact color codes.  But the MSD box needs one constant 12V source usually attached to the starter solenoid at the + battery cable stud, and one switched 12V source that has 12V when cranking and in the run position.  I went directly to the ignition switch for that.  The MSD box attaches to both the + and - coil terminals and the distributor.  The original + wire to the coil does not and cannot be used because it has a resistor wire in the circuit.

 

I am guessing the switched 12V wire to the MSD box does not have power while cranking.  When you use the remote starter button on the solenoid you have your ignition switch in the run position supplying the 12V to the switched 12V wire to the MSD box.  Does that make sense?

I used the + wire from my old coil for the switched power to my 6AL box and it works fine. Do you think I should change this due to the risk of possibly damaging the box?

[1969_Mach1 333]

I don't know if long tern damage will result if the 12V switched voltage to the MSD box is too low.  I vaguely recall a friend of mine I worked with about 25 years ago in a repair shop connected his MSD box the way you did on his 67 Fairlane.  He bracket raced the car so it had a well built high compression Cleveland in it.  His MSD boxes would not last very long or intermittently the car would not start because of no spark or weak spark.  He replaced or repaired the box a couple few times through MSD warranty before he realized the resistor wire issue.  He bypassed the resistor wire and after that I don't recall any more MSD issues.

 

I try to follow the mfg. instructions otherwise if something doesn't work correctly I start wondering if a component failed, or is it because of something I did differently, or did a component fail because I did something differently.  Plus if you ever need a warranty repair, an incorrect installation usually voids any warranty.

 

Edit:  Currently, the way it's connected you are getting 12V to the MSD box while cranking due to the factory resister bypass wire that it attached to the starter solenoid.  After that, the voltage would be reduced because of the resistor wire (providing a PO hasn't removed it).

[JXL 12]

Ok so just to clarify, when cranking it over it is getting 12v and then when in the run position it is reduced to something lower than 12v. I will put a multi meter on the wire this weekend and check it out. Do you know where the resister is? I will bypass it if I can find it. Thanks for letting me know about this. Wrecking the box would suck but having it frig up when I am out in the car and causing it not to run would be worse!

[1969_Mach1 333]

I am assuming you Mustang is a 1969 and does not have a factory tachometer.  So, without the factory tachometer the resistor wire starts at the ignition switch, it is about 4 feet long, wrapped inside the under dash harness and ends up at the three terminal connector near the drivers side valve cover close to the firewall.  I attached a new wire for the MSD's switched 12V to the ignition switch at the same terminal the resistor wire is attached to.  I left the resistor wire in place and didn't use the other end of it.  That terminal on the ignition switch should have 12V in crank and run only.  The resistor wire was originally a shade of pink, it has a thicker than normal and more rubbery insulation, and fewer wire strands than normal.  The resistor wire's strands are not copper and are silver in color.

 

At the ignition switch I had to remove the terminal from the plastic connector, open up the crimp holding the resistor wire onto it, then I soldered my new wire to the terminal.  It might be easier to buy a replacement ignition switch wiring pigtail instead of working with the original.  Here is a link for a pigtail at CJ pony parts.  I usually use NPD but their catalog picture was wrong.  The picture clearly shows the resistor wire included with the pigtail.

 

http://www.cjponyparts.com/scott-drake-ignition-switch-wiring-pigtail-1968-1969/p/HW3125/

[JXL 12]

Ok, thanks for the info. I will take a look at it this weekend. Yes it's a '69 Coupe with the 351w. I attached a couple pics of it below I think, not sure if I did it correctly.

[1969_Mach1 333]

Nice.  I always like brighter colors.  Is that a factory color?  In high school a friend of mine had a 70 Mach1 still with original paint that was very close to yours.

[JXL 12]

It is competition orange. I think it was a factory option in 1970.