How to trouble shoot MSD 6AL?

The 6AL has three cables going into it for power. Two red and one black. The black is, of course, your ground wire. The thicker of the two red wires (the one coming out with the black wire) is your main power cable. On my setup this wire is always hot. The smaller red wire is the one that tells the box when to energize. If it does not provide power to the box during cranking then the box will remain in an off position and provide no spark.

I had a tough time finding a source that remained hot during start but eventually I was able to tap into it and everything worked as advertised.
 
MSD has troubleshooting on their site AFAIK. If it officially flunks their own tests, I'd call 'em up and see if they want your box.

Good luck.
 
Make sure that the smaller red wire still has power (9-12V) while the engine is cranking. Not just with the key on. That's where my problems appeared. Most of your electrical system will shut down during cranking so that your starter has all the juice it needs. I had to locate a "hot in start" power source.

Other than that check to make sure that the coil and distributor connections are sound. The 6AL is pretty much an on or off piece of equipment according to MSD. It either works or it doesn't. I went through the same thing when I installed mine but once I got the wiring set up everything worked great.
 
The tests on their site (I haven't looked in a while but they used to have pretty decent testing procedures) will still help you narrow down where the issue lies. It should take but a few minutes to do.

Good luck.
 
Ok, it has teh 12v power wire, and the 12v going to it when cranking for the smaller wire( drops down to like 10/11 or whatever when its cranking but there is power going through it).

I found this in the instructions via summits website

CHECKING FOR SPARK
If triggering the ignition with the White wire:
1. Make sure the ignition switch is in the "Off"
position.
2. Remove the coil wire from the distributor cap
and set the terminal approximately 1/2" from
ground.
3. Disconnect the MSD White wire from the
distributor's points or ignition amplifier.
4. Turn the ignition to the On position. Do not crank the engine.
5. Tap the White wire to ground several times. Each time you pull the wire from ground, a
spark should jump from the coil wire to ground. If spark is present, the ignition is working
properly. If there is no spark skip to step 6 below:

I dont get step two, would i just disconnect the dizzycap to coil wire and then take the white one coming from the MSD and tap it?
 
It's been a while but the directions are correct. The white wire tells the box when to send a spark signal. It's kind of a juggling act to keep the coil wire close to a ground and make contact with the white wire to ground but it does work. That is, if the box is working.
 
You can also toss an old spark plug in the coil wire and set the threads of the plug on the plenum. This takes the guesswork out of wondering if the air-gap is too great. A spark tester can also be used.

Were you the one who had issues with your stereo? If so, you might end up having an ignition switch issue causing the issues.

Good luck.