merc 3.0 blowing ign. fuse when shifting out of gear, stall switch causing problem?

[arborist83]

will the stall switch blow my ignition fuse if held excessivly long? is my main question. I have a plunger type stall switch,ground(black) to carb and purple wire to the distributer, When the boat is warm, and in the water, I manually plunge the stall switch the ignition fuse blows, only happens when motor is warm. I have disconnected everything from the fuse block except the ignition, again if I plunge and HOLD the stall switch it blows the ignition fuse, is this normal, maybe my cables need adjustment or replaced because they are holding the plunger excessively long and blowing the ign fuse? any thoughts or help, thank you, I also heard the coil may be faulty when warm is thjis true?

 

[dubs283]

Re: merc 3.0 blowing ign. fuse when shifting out of gear, stall switch causing proble

the shift interrupt switch controls the negative side of the coil primary, this is basically the "signal" side that tells the coil when to fire out the tower

it sounds as if you have the switch wired to the positive side of the coil which would put the ignition (+) voltage directly to ground, thus blowing the ignition fuse

what is the serial number of the engine so we can get you a manual with a wiring diagram??

 

[arborist83]

Re: merc 3.0 blowing ign. fuse when shifting out of gear, stall switch causing proble

thank you for your input, here is the serial number for the motor 0f075877

and a link http://forums.iboats.com/showthread.php?t=486043&highlight=ignition

I think this is correct for a diagram I got from another thread, I tried putting the wires to purple and green white on the distrib as as directed by the link, the switch does not work when wired that way. I will be dropping the boat at my mechanic today so other suggestions will be on hold till tonight when I go to him. Also it is possible that the old roller style switch was replaced with the plunger style setup with the shift assist, if so would this change the wiring. also could my coil be no good or is there another part on the distributer that could be bad. thank you again

 

[Don S]

Re: merc 3.0 blowing ign. fuse when shifting out of gear, stall switch causing proble

You shouldn't be using that thread at all. He was trying to replace a Thunderbolt ignition with an EST, and you are now trying to match up wires to colors that don't exist on your engine.
It's fairly easy to troubleshoot that system. but since you are taking it to a tech, he can figure it out.

 

[arborist83]

Re: merc 3.0 blowing ign. fuse when shifting out of gear, stall switch causing proble

well not really because the mecanic is not sure either, he's the one who hooked it up! I think the distrib electronics are trash and needs to be replaced, is this possible? I have the purple wire and the white/green wire to the distrib hooked up to the interupter, isnt this right? Don what is the proper setup for my motor, I'll look thru the adults only for now but any suggestions appreciated

 

[arborist83]

Re: merc 3.0 blowing ign. fuse when shifting out of gear, stall switch causing proble

also Don in the adults only section I downloaded the manual the ignition system wires are all exactly the same I have it hooked up properly, I will replace the coil and the pickup on thge distributor and report back.

 

[arborist83]

Re: merc 3.0 blowing ign. fuse when shifting out of gear, stall switch causing proble

Don the second diagram is correct