Bad key ignition, I think?

4runner02

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I have a 1988 Wellcraft Classic 170 with a 3.0L Mercruiser, 181 CID, 130 HP, #831646. I was having problems with it starting sometimes and not others. Finally it just stopped starting. Got home by jumping the probes on the starter.

At home with a test light I tested the key ignition; red battery cable was hot, ACC lit when key was turned, and SOL lit when turned to start the engine. Went to the engine compartment and found out the slave solenoid was bad. Replaced it. The boat still won't start.

So I started over with the test light. Only this time on the key ignition when the key is turned to ACC the red battery cable, which should stay hot, goes dead. If the key is turned back to the off position the red battery cable becomes hot again and the test light goes back on. I followed the hot cable back to a wiring harness which I pulled apart and tested female end and it lit up so juice was at least getting there. I believe then the problem then is some where between that harness and the key ignition.

Any ideas? Please help. I've only used the boat 3 times since I got it and the kids are dying to get back out on the water.

Thanks.
 

Don S

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Re: Bad key ignition, I think?

Leave the key in the run position and check voltage on both terminals of the circuit breaker with the red/purple wire. Also make sure the round harness connector is making good contact.
 

4runner02

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Re: Bad key ignition, I think?

Here's an update from last post:

I thought maybe it was a bad key ignition so I got a new one. Most of you already know that that wasn't it, and you are right. Same as before, but I wanted to rule it out. I can always return it.

But, on a whim, I connected a wire between the hot lead on the fuse panel and the key ignition with the harness in between undone. Sure enough, the thing turned right over. To shut it down I had to remove the main distributor wire so this is not a viable work around.

Does it sound like there could be a short somewhere between the harness and the key? And why did this just start now after replace the slave solenoid?
 

Don S

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Re: Bad key ignition, I think?

Didn't read my reply did you?
 

4runner02

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Re: Bad key ignition, I think?

Don,
I don't have a voltage meter. I guess I'll have to pick one up. I'm new at all of this so you'll have to bear with me.

The harness under the dash is square. It seems to be fitting properly. I even pulled the cannon plug harness off the engine and cleaned any corrosion off of both.

When you say to check the voltage of both terminals on the circuit breaker, do you mean put one probe of the voltage meter on one side of the fuse and the other probe on the other to get the reading?

And by the way, while writing this post I went back out to the boat to check the fuse panel to make sure the purple wire went there (I told you I was new) and noticed the trim light gauge was on. I must have left the key in the run position. So I turned it, and sure enough it started. Could would I have done in my last post with running that wire directly from the hot cable on the fuse panel directly to the key ignition do something? I had already disconnected that wire so I know that wasn't why there was juice flowing. I don't believe it was the new key switch either, because it still hadn't started after I had just it in.

And thanks for your help.
 

4runner02

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Re: Bad key ignition, I think?

I did, Don, but only after I had gone back out there and tried that. I'm sheepishly grinning right now.
 

Don S

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Re: Bad key ignition, I think?

You don't need a volt meter, just use your test light. Hook the clip to a good clean ground and see if the light comes on full bright when you touch it to the terminals on the circuit breaker.

I also doubt they will take back your 'now used' ignition switch just because it didn't fix your problem. They can no longer sell it as new, and they shouldn't be expected to loan you new parts to test your system :facepalm:
 

4runner02

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Re: Bad key ignition, I think?

OK, I just tested and everything lights up nice and bright. Is there anything else you can I should do? Or do you think it's fine now? I'd hate to get out on the water and not be able to restart it. The wife would not be happy even though I know how to hot wire it.

And you're right about the key switch. I'll keep it as a spare. Karma and all.
 

Don S

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Re: Bad key ignition, I think?

Did you have the key on when you tested it? When you have something pulling power is when you loose it.

Just curious, how did you have your test light hooked up when you found no power on the battery terminal of the switch?
 

4runner02

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Re: Bad key ignition, I think?

Yep the key was in on position. I had the test light attached to the negative line out of the fuse panel. Is there a better place to attach it?
 

Don S

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Re: Bad key ignition, I think?

No, that's where it should be.

If you don't have power on the red or red/purple wire on your ignition switch when the key is turned to run, and you do have power when the key is in the off position, then you have a problem between the battery and the ignition switch.

Since you can jumper the starter means the battery cable to the starter is ok. So it has to be in the red wire from the starter to the ignition switch.
 

4runner02

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Re: Bad key ignition, I think?

Thanks very much for your help, Don. It's nice to see some one taking the time to help a newbie. It seems as of now everything is fine, but I'll check that red wire from the starter to ignition for any shorts/cuts.
 

4runner02

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Re: Bad key ignition, I think?

And it was your troubleshooting guide that got me to find out that it was the slave solenoid to begin with. You are the man!
 
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