Engine still runs with ignition key off

[rmdhokie]

New member, new boat owner, first time post.

I have a 1999 Wellcraft 186S with Volvo Penta 4.3 GL (PWTR) and SX outdrive.

I just bought the boat; engine starts and runs great. Compression test completed and checked good (all cylinders 165-175). However, with the motor running, the boat will not turn off with the ignition key (or pulling the kill lanyard). Right now, I have to pull the coil lead from the distributor cap to kill the engine. I would appreciate some suggestions/expertise. The following are actions taken so far.

1. Tested the ignition switch (3-post). With the switch in off position, I have 12.78 volts on the red/purple wire, 0 volts on purple and yellow/red wire on the back of the switch. With the switch in the run position, I have 12.78 volts on both the red/purple and purple wire and 0 volts on the yellow/red wire. Moving the switch to the start position, starts the engine. With the engine running and switch in the run position, there is 13.96 volts on both the red/purple and purple wire and 0 volts yellow/red. However, turning the switch to off, the engine still runs and I still have 13.96 volts on both the red/purple and purple wire and 0 volts yellow/red.

2. Tested the coil. I have 12.76 volts on the purple wire at the coil with the switch in the run position, but 0 volts when the switch is in the off position. This test was done with engine off. Coil must be getting power to continue running, right? Stumped.

3. Checked and cleaned main wire harness and plug. I have 12.76 volts on the purple wire/pin on plug with the switch in the run position, but 0 volts when the switch is in the off position.

4. Intermittent operation. I found that when the remote control is in neutral without any throttle applied (handle straight up) that the engine with start AND kill with the ignition switch. However, when the remote control is in neutral with some throttle applied (handle slightly forward) the engine will start but NOT kill with the ignition switch. The engine won't start in gear, so the neutral safety switch is good, right? Stumped.

I?ve read some forums that mention the alternator or resistor wire on the alternator that might cause this issue, but I?m not sure how the test or isolate the resistor wire without taking out the alternator and getting it tested.

Any help/suggestions would be great appreciated. Thanks.

-Rob

 

[vegasphotoman]

Re: Engine still runs with ignition key off

replace Ign switch? looks like it isnt disengaging all the time...

.or unplug the purple wire while its running...if engine dies...BAD SWITCH would be my best educated guess.........

or find wiring schematic and figure what each wire is for......
I would assume one is power all the time = red/purple wire

.....one for power to go to starter solenoid momentarily = yellow/red wire

....one for power to coil (run position) = Purple

 

[JustJason]

Re: Engine still runs with ignition key off

99% sure its the alternator. Pull the wire(s) off the back of it or just loosen it up and take the belt of and see if she starts and stops then.

 

[Don S]

Re: Engine still runs with ignition key off

I?ve read some forums that mention the alternator or resistor wire on the alternator that might cause this issue, but I?m not sure how the test or isolate the resistor wire without taking out the alternator and getting it tested.

That is the kind of BS that makes forums bad. You read things that has nothing to do with your setup. You don't have a resistor in the alt. system.
You pull all the wires off the alternator, and the fuel pump won't work. Now it'll stop.

 

[Don S]

Re: Engine still runs with ignition key off

Here are the OEM service manuals for your engine. Might want to start looking at them. Especially the one on the electrical system.

http://www.4shared.com/dir/14518373/c484ddd4/WTsharing.html

 

[bruceb58]

Re: Engine still runs with ignition key off

Yes...the problem with taking off all the wires off the back of the alternator is that one drives the fuel pump. The excite wire to the alternator is the purple wire. If there is something wrong with the regulator that keeps the excite connection energized, the engine will not turn off.

Does this boat have the original alternator on it and are all the wires on the alternator as indicated in the schematic in the manual that Don posted?

What is your charge voltage? I would suggest to do the tests for the regulator as outlined in the manual in the charging section.

 

[rmdhokie]

Re: Engine still runs with ignition key off

Appreciate all the feedback. I'll do the test on the voltage regulator and post results. Thanks.

 

[JustJason]

Re: Engine still runs with ignition key off

You pull all the wires off the alternator, and the fuel pump won't work

Yes...the problem with taking off all the wires off the back of the alternator is that one drives the fuel pump.

I didn't even think of that. Either way, if this is a carbed motor, there should still be enough fuel in the bowl for it to run for 20-30 seconds ad idle. All you need to do is start it up and turn it off to confirm the diagnosis.

 

[Don S]

Re: Engine still runs with ignition key off

All he has to do is disconnect the purple wire from the regulator. Does the same thing. Isolates the purple wire from the alternator.

 

[bruceb58]

Re: Engine still runs with ignition key off

Or you can pull the wire off that goes to the fuel pump and connect it with a jumper to 12V temporarily. Then take the purple excite wire off and see if it is causing your problem.

 

[rmdhokie]

Re: Engine still runs with ignition key off

Problem fixed. It was a problem with how the fuel pump was wired to the alternator. Appreciate the assistance and the manuals. Motor now turns off with the key.

Next task: replace shift control cable.

 

[Don S]

Re: Engine still runs with ignition key off

Come on now, you aren't getting off that easy. Explain what was wrong so someone else might be helped. HOW was it wired wrong, wire on the wrong terminal????

 

[rmdhokie]

Re: Engine still runs with ignition key off

The wire for the fuel pump (not OEM wiring) was hooked to the wrong terminal on the alternator. It was was hooked to the "EXC" instead of "L2" terminal as indicated in chapter 8 of the electrical manual Don S provided.

I also tightened the alt belt and tested the alternator's wiring harness, ignition circuit, and excite/sense circuit according to chapter 3 of the electrical manual. All tests were pretty simple and my alt passed all tests.

Although my boat now starts and stops via the ignition key, tracing what appears to be a previous wiring repair from the alternator to the fuel pump, I know that there is not a diode currently in line as indicated in the wiring diagram. Will this cause any trouble? I'm not sure, but will probably replace it anyway.

 

[steddy]

Re: Engine still runs with ignition key off

The wire for the fuel pump (not OEM wiring) was hooked to the wrong terminal on the alternator. It was was hooked to the "EXC" instead of "L2" terminal as indicated in chapter 8 of the electrical manual Don S provided.

I also tightened the alt belt and tested the alternator's wiring harness, ignition circuit, and excite/sense circuit according to chapter 3 of the electrical manual. All tests were pretty simple and my alt passed all tests.
QUOTE]

There you go!
I agree: "Wired Wrong - Fixed" just doesn't satisfy. We needed more closure.

 

[Don S]

Re: Engine still runs with ignition key off

Although my boat now starts and stops via the ignition key, tracing what appears to be a previous wiring repair from the alternator to the fuel pump, I know that there is not a diode currently in line as indicated in the wiring diagram. Will this cause any trouble?

It could damage the alternator. When you engage the starer, power would be put on the L2 terminal by the pump relay. Which it shouldn't do.