TOPIC: 72'Mercury 50hp. pwr.pack/switch box bench test?

How do you bench test a power pack/switch box. Last used motor two yrs ago(it ran but never came up to full power). Now I can't get any spark.Out board repair guy says I need new swich/power pack box? How can I bench test mine to be sure it's not someting else?
thanks,
delvel

I'm not sure there is a way to test the switchbox, but perhaps with a dva meter if you can find the specs.
First thing you want to do is disconnect the mercury safety switch and test for spark.
You can test the trigger (distributor) as per the manual & you can do an ohms test to the coil, and by process of elimination identify the switchbox as the culprit.
Do you have a cdi ignition (round aluminum body with a round distributor cap) or a Lightning Energizer (somewhat rectangular aluminum body & a yellow rectangular cover)??
I usually spread all (3) components out on the bench, haywire them together, and use known good components in place of each one in question until I identify what needs to be replaced. That calls for having some good used extra parts laying around though.
Since the distributor is difficult to remove, you can also leave it in place and hang the test components off to the side rather than going to the work bench.
If you have a Lightning Energizer ignition - do NOT apply 12vdc to any of its terminals - not even the red one or you will instantly fry that switch box. The LE creates its own spark.
If you want to contact me direct and discuss mailing these parts to me to trouble shoot and replace the faulty component, feel free to write. frankenmerc at comcast dot net

If you have the lightning energizer i hav one complete or some parts.

Thanks Doc:
I did a little exploritory surgery yesterday. tURNS OUT that the internal wire harness is all corrodide and the coating on the wires is all crumbling off(short circuting?). I'm going to remove it and re-wire see if thats why the switch bx is not working. I'll keep you informed.
thanks,
Gene

thanks dave:
I'll keep that in mind.