Mercury 15HP outboard

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If he connects the 2 wires together he will have no spark.That is how the kill button works on all 3 of my Mercs.

sorry fellers i was typin faster than i can think

if your not getting spark you need to start back probing.

take your plug out and hook the pos lead of your meter to the end of the plug wire and the neg lead to the engine block. have a buddy turn the motor over. any voltage?

if not unplug the wire from the coil and do the same. if nothing ohm the coil out. whats your reading?
 
I'll try this when I get home from work.

Take the plug out, hook positive to spark plug cable and negative to engine block. Try turning engine over and get the voltage reading. Correct?

I'll report back later.
 
yah man. if you dont get anything disconnect the plug wire at the coil and see if your getting any V there.

if still nothing ohm your coil and get back to us
 
After doing some testing, I am positive the kill switch works properly.

I used a Spark Plug tester to eliminate the possibility of the spark plug being no good. Even with a new plug, I was still getting no spark.

I used a Fluke 87 DVM to measure the voltage at the switchbox. The voltage registered just a tad above 3V.

Granted the electronics on this motor are nearly 21 years old, is there a possibility the switchbox could go bad.
 
Of the Mercs that I own I have had 1 switch box bad & 1 trigger.Mercs are hard to trouble shoot electrical.Even if part test good it still could be bad.(almost a direct quote from a Merc shop manual)
 
Where I should trouble shoot from here? I'm hesitant to order a new switch box, because they go for a little over $100.
 
Last weekend though I had the opportunity to mess with the motor some more. I was finally able to get her started, but let me tell you the story behind it.

August 22nd was when I began having problems with the motor. That night, it had rained pretty hard and the next morning there was very dense fog that came over us. I didn't think much of it then, but I remember taking the cover off the motor when it wouldn't start and the entire engine was covered in condensation. I figured since it was a marine motor, it has probably been wet before. So I came to you guys in hopes of figuring out why it wouldn't start.

After putting a multimeter on everything you guys were telling me to, I was still hesitant to buy a new switch box. I ended up going away to college and for two weeks I left it in my garage back home with the cover off and spark plugs pulled. I kept thinking that maybe the condensation I had seen weeks before had caused the problems. This was going to be my last attempt before buying a new switch box.

I'm still unsure whether the condensation caused the problem or not, but I know everything in the engine should have been pretty dry after two weeks. I pulled the boat out and primered the engine just as I had in the past and the engine fired up on the second pull. I couldn't believe it and I am still in shock and disbelief.

I just want to thank you guys for the help and check out my build log once I post it later.
 

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