I finally was able to get a dock side mechanic to look at motor. He knows just a little more than me so after calling 6 yes 6 different people I was glad to see him. Long story short . When we switched ECM mounted on heat sink and 6 coils and spark plug wires from other motor it worked. Any possibility it could be anything else in the assembly besides the ECM? He says I need a ECM which I can buy myself. $1800.00 list. I have not started shopping. All mechanics in FL.Keys are way too busy. Thanks for any input. John
Part of this is irrelevant. The coils and plug wires have no power when engine is off or even with keyswitch to the on position.
Don't throw your money away yet, or send me some for saving you a ton of $$.
First, remove blown fuse. Connect meter red lead to one side of fuse and black lead to ground, use volts DC scale. Turn switch to on, should read 12+ volts. If not, connect red lead to other side of fuse, now should see voltage.
Now we know which side of fuse is positive/negative side, turn switch off. Now connect red lead to negative side of that fuse block, connect black lead to engine ground. Turn meter to ohms scale. Since we know something is shorted/grounded, the meter should read > 1 ohm. If it was ok, the meter would read 0 or infinity.
Now, all you can do is start disconnecting the wires to each component (which is fed from the negative side of the fuse and this could be quite a few different wiring connections). You really need a wiring diagram unless you know the engine wiring. Most people don't and even with a diagram it can get very confusing.
For each wire you disconnect, look at meter. When resistance goes to 0 or infinity...You've now found the problem!