Electrical gremlin....ignition went dead...help!

craze1cars

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As many of you know, I recently removed the drive and bellhousing to replace all bellows & both trim senders. 1992 Mercruiser 3.0 Alpha 1 Gen II. I took a week's vacation and am now back at it and just about done with re-assembly. Here's my quandry:<br /><br />I was about to adjust the new trim senders and tried to turn on my ignition so I could read the trim guage. Dead, nothing, nada. No dash lights, no clicks, no engine cranking. It worked 2 weeks ago before I did the bellows project!<br /><br />Battery is hooked up and fully charged, all non-ignition items are working fine (fish finder, horn, lights, radio).<br /><br />And yes, it's in neutral. However I first suspected something may be amiss with the neutral switch/engine interrupt switch (whichever it is up there by the shift cable) since I had to remove the shift cable to do the bellows project. It is centered as it should be and the switch is "out." When the switch is out, the circuit is wide open, when I push the switch in (forward or reverse), I have full continuity. I presume this means it's working like it should. I tried turning the key in both positions just for kicks and dead both ways. I tried the "reset" switch on the motor. All fuses are present and have continuity. All visible electrical connections are tight. The ONLY electrical connections I messed with between then and now was the 4 plugs for the trim senders. These wouldn't cause the ignition to die, could they? The drive is still off the boat (waiting for my alignment tool before reinstalling), again I can't imagine that would affect my ignition circuit, but am I overlooking something obvious? I'm stumped and not sure where to turn.<br /><br />Stupid, stupid me and wasting money on that Clymer's manual...their troubleshooting charts are useless and don't even cover a basic no-ignition sequence so I'm not sure where to start. Is anyone out there able to post me a quick Mercruiser troubleshooting guide so I can systematically attack this thing and find out why I'm suddenly not getting juice? Any suggestions on where I should start? Much appreciated if anyone has some ideas.
 

Fishermark

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Re: Electrical gremlin....ignition went dead...help!

I'm not sure if it would be the same on your boat or not, but my Dad's boat had an inline fuse on the ignition circuit up inder the dash. You may check there and see if your's has one or not.
 

Dunaruna

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Re: Electrical gremlin....ignition went dead...help!

Took me three hours on the weekend to diagnose and fix the same problem. Boat just died - no voltage anywhere, zip, nada.<br /><br />Use an OHM meter, start at the battery and work your way through the ignition switch and onward. You will probably find a connection that looks o/k - but it ain't. The all knowing and mighty OHM meter will seek out these bad connections.<br /><br />Mine was the main ignition fuse, the fuse itself was o/k but the spring loaded connections were not.<br /><br />Aldo
 

Don S

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Re: Electrical gremlin....ignition went dead...help!

I would just use a test light hooked to a good ground and start at the battery and follow the red and red/purple wires till you find where you loose the power. Use the wiring diagrams fo the engine shown above to the circuit breaker and main plug at the engine. There is also a soldered splice in the wireing harness that may have come apart. Look at the wiring diagram and check out the different legs.
 

rattana

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Re: Electrical gremlin....ignition went dead...help!

Is your battery ground wire connected to the engine block?
 

craze1cars

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Re: Electrical gremlin....ignition went dead...help!

OK, thanks for the tips. Apparently there's no obvious magic pill here related to what I've been doing with the drive. I've already been chasing with a meter since I posted this, as you suggested. I still have a full 12.6 volts (same as battery) at the hot wire on the ignition switch but for some crazy reason it seems to drop off to 9.5 depending on which time I tested it?!? I'm thinking I have some corroded connections that are varying my voltage and current, or maybe just the switch itself is bad...but I still couldn't get any power even after jumping the switch. That's all I tried, ran out of time last night and stopped there...I'll continue chasing this evening after I bring home a better quality meter from work that will make testing a whole lot easier. Probably a completely unrelated coincidence, just really surprised me. Welcome to boating, eh?!
 

muc

"Retired" Association of Marine Technicians...
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Re: Electrical gremlin....ignition went dead...help!

Check the 10 pin cannon plug. It's on the engine. Take it apart and spread the pins a little bit and give it a good cleaning.
 

craze1cars

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Re: Electrical gremlin....ignition went dead...help!

A good hour with a multimeter and I got it. Traced it to a fuse under the dash that was fine, but wasn't making proper contact due to corrosion. A little emery cloth & tab bending and problem solved...concidence and completely unrelated to what I was trying to fix. Anywho....that's twice I've screwed with cleaning connections in this fuse block now. Methinks I'm going to just replace it with a new one and end this...
 

Dunaruna

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Re: Electrical gremlin....ignition went dead...help!

Now you know where it is, It'll be the first thing you check next time ;) <br /><br />Aldo
 

Fishermark

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Re: Electrical gremlin....ignition went dead...help!

Those glass inline fuses are WORTHLESS on a boat. I have no idea why they use them. I generally remove them and use an inline blade fuse with a cover. Holds up to corrosion, etc much better IMHO.
 

craze1cars

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Re: Electrical gremlin....ignition went dead...help!

Thanks Fishermark...I was thinking much the same thing. Autozone didn't come through fo me this time, but today I donated $25 to my local NAPA store in exchange for a "Buss" brand 10 circuit bladed fuse box complete with spade terminals and everything....looks like a perfect replacement for my old glass tubed fuse box. That should eradicate any electrical gremlins from this location. Thought I'd share my find in case others have had similar bad luck with the old-fashioned and unreliable glass fuses.
 
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