NHGuy

I can mess up anything.

I feel pretty stupid. I know enough to power down the engine while working on it and I still messed up. I touched the main post on my alternator while assembling my power steering and now I have no spark. This was done while the key was off.

There's no spark now, I went as far as disconnecting my shift interrupt and then checked the output circuit. It has battery voltage.
But there's no fire at the plugs, and there was before this muck up.

I have the manual and I was going to next test the excitation circuit, and then the sensing circuit.

I am not much of an electrician, But with the good weather we expect I want to dunk the boat.
After reading the electrical diagram it appears that the only pieces in the line of fire are these.
I happen to have a new regulator/brush assembly. And I bought a new rectifier bridge this week in case I need it.
What else do I check, anything?

AllDodge

iTrader: (1)

On the starter post there is a square item which also has (in most cases) a Red/Purple wire which goes to the 50 amp breaker and a Orange wire which goes to the alternator. The square item is a 90 amp fuse which has probably been blown. If you have battery volts on the starter post and none on the 50 amp breaker or small post on square fuse, then the fuse was blown. The square thing comes apart and the fuse is inside

https://leadersrpmshop.com/mercury-marine-mercruiser-new-oem-fuse-90-amp-88-8m6001960/?gclid=Cj0KCQjwgLLoBRDyARIsACRAZe5iK2vaqT0EeFOXikp H4TFk-JMbhTSAHW_efGxnIuO4HUSZMdSzIBAaAiPhEALw_wcB

https://www.amazon.com/Mercury-Quicksilver-Fuse-Assy-90-Amp/dp/B0038ZYPSW/ref=asc_df_B0038ZYPSW/?tag=hyprod-20&linkCode=df0&hvadid=312684231807&hvpos=1o1&hvne tw=g&hvrand=17503518789781838511&hvpone=&hvptwo=&h vqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9014831 &hvtargid=pla-568793613346&psc=1&tag=&ref=&adgrpid=60983009663&h vpone=&hvptwo=&hvadid=312684231807&hvpos=1o1&hvnet w=g&hvrand=17503518789781838511&hvqmt=&hvdev=c&hvd vcmdl=&hvlocint=&hvlocphy=9014831&hvtargid=pla-568793613346

NHGuy

That would be save! Will check it in the AM.

Crude Intentions

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ICDEDPPL

iTrader: (1)

How do you know ?

NHGuy

FINAL SOLUTION
It turns out that my engine does not have the 90A fuse on the starter post.
So.as is typical the coil tested bad at first. But we all know coils rarely fail so I retested with the correct ohm scale and unplugged from engine harness - the coil was actually good.
I have a DUI distributor, which is just a modernized clone of the GM HEI from the 70's. I called Davis Ignition and he thought it would be the module. It turns out it was.
I'm back in business.
I hope if someone else does the same dumb thing I did they can learn from my mistake.

Crude Intentions

iTrader: (1)

Crude Intentions

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justinp20012500

I just did this.... Hanging upside down trying to get the SOB off the starter relay was fun. I now carry an extra 90amp fuse in the boat for when I or someone else grounds the charge post.