Engine will not shut off

[DarrinT]

I posted this on the engine forum but I'll see if you guys might have had this problem that might be specific to an engine swap from another boat to a starcraft:



1973 Starcraft Islander 140 Mercruiser restore project

Just swapped engine , outdrive and tilt rams from a 71 Larson donator boat following the manual and being as careful as an ignorant amateur can be

I have a short somewhere in my system and I can't turn the motor off at the key switch.

When I connect the battery the lights come on in the dash and when I run the motor it will not shut off unless I pull the wire off the coil.

I disconnected the ignition switch and the lights still come on in the dash

I'm trying to determine if the fault is at the engine or dash so I pulled the main connector that brings the wires from the dash to the engine when the engine was running thinking that this would kill the motor - but it kept running.

Should this happen?

Also when I start the motor the ammeter stays flat for a minute or so then jumps to indicate its charging the battery. I'm beginning to suspect the ammeter is the problem but being a total electrical neophyte I'm afraid if I mess with it too much I might blow something up.

All help and comments greatly appreciated

Thanks Darrin

 

[cedarjunki]

Re: Engine will not shut off

was this boat working/running properly before the swap?? or unknown? disconnecting the harness may be a bad idea...possibly cause damage to alternator.

any wires under the dash look like they have been spliced or tapped into?

 

[DarrinT]

Re: Engine will not shut off

Both engines workin fine except I cracked the head on the swapped out one and I'm leery of a repair on a cracked head. Runs great just won't shut off and the wiring looks good. I just not sure if unplugging the harness should kill the engine.If it should kill the engine then the harness or some other part of the system on the engine is bad. If the engine would normally run with the harness unplugged then its back to square one.

 

[cedarjunki]

Re: Engine will not shut off

sounds like time to pull out a wiring diagram and start tracing wires :/

are you using the engine harness from the donor? or did you disconnect all the wiring?

 

[DarrinT]

Re: Engine will not shut off

Used the same harness on the "new" engine

 

[cedarjunki]

Re: Engine will not shut off

then its going to be a simple misplaced wire if the original wiring is still be used.....double check the coil wires and wires running to the starter.

do you have or did you download the maual for the wiring diagram? if not check the adult section.

 

[Canman38]

Re: Engine will not shut off

ok, where is this "adult section" that you speak of? sorry i searched and couldnt find it

 

[Huron Angler]

Re: Engine will not shut off

ok, where is this "adult section" that you speak of? sorry i searched and couldnt find it

Here's a link to the I/O forum, ADULTS ONLY is the first thread.

 

[Kainon]

Re: Engine will not shut off

I read you disconnected the wires at the switch.

3 wires to the ignition switch, 1 Purple from the I-Ignition to the tach, 1 purple/Red from the Harness TO the B-BATT Connection and Yellow/Red to the S-Start which goes to the Shifter (Start/Neutral Safety Switch).

Somehow you are powering the PURPLE Circuit, this sends 12v to the Coil ( which is bad if your running points )

The Ammeter Gauge has 2 thicker 12+ wires to it, and measures the amps flowing by. Even if bad wont cause the engine to not shut off.. It can cause you to have NO power At the Dash.

Check out this thread.

http://forums.iboats.com/showthread.php?t=167035

 

[starcrafter65]

Re: Engine will not shut off

Beleive it or not - had the same. The purple wire in the harness is the "live wire" that is common to guages and coil. I had everyhting at the key hooked correctly. The key has a hot lead (red) - a feed to the starter - and a purple feed (ignition). This purple should be a pigtail (connector) to a common stud on the RPM meter - the other purples tie into this.

Somewhere your purple is still live!

What happened to me was the big fat lead that came off battery and went to the starter (hot) connection on the motor had a big long connector on it at the engine - and actually was touching the stud which the purple common came off of next to it - making the engine "live" all the time. So I had a short from the hot to the purple. I would look for that.

Or - better than not running!

 

[DarrinT]

Re: Engine will not shut off

Thanks Guys

I'll get to work

 

[DarrinT]

Re: Engine will not shut off

Oops the wires that I have coming from my key switch are red/white (I) , yellow (S) and white (A)

The purple one is used for the oil pressure switch and runs to a warning light on the dash and then to the oil pressure gauge

this agrees with wiring diagram from the Seloc manual

so on my boat it is the red/white that should not have power in it?

 

[DarrinT]

Re: Engine will not shut off

The white wire dives into the harness on the engine and does not come out

The wiring diagram shows that it turns into a "resistance wire" then connects to the coil but that does not seem to be the way its set up in other words no whit wire goes to the coil

 

[starcrafter65]

Re: Engine will not shut off

Whatever color went to the Ignition post on your key is the power to the coil.

Somehow - somewhere this wire is getting power to it.

Try your battery connections to the motor (that is where mine was shorted)....or possibly your key is malfunctioning.

Do have a multimeter?

 

[cedarjunki]

Re: Engine will not shut off

The white wire dives into the harness on the engine and does not come out

The wiring diagram shows that it turns into a "resistance wire" then connects to the coil but that does not seem to be the way its set up in other words no whit wire goes to the coil

that white wire comes out to the two resistors then brown to the coil on mine.....not all have the resistors.

 

[DarrinT]

Re: Engine will not shut off

Success

The frigging main positive battery connector at the starter was touching the post next to it

5 or 6 hrs of grief later my handy buddy was helping me trace wires with a newly purchased multimeter and he spotted it - in the dark with a trouble light

I had only spent hrs in the daylight comparing the wiring diagram to the wires on the engine and still didn't spot it

Thanks guys for all the suggestions that kept me at it

These forums rock

 

[cedarjunki]

Re: Engine will not shut off

Success

The frigging main positive battery connector at the starter was touching the post next to it

5 or 6 hrs of grief later my handy buddy was helping me trace wires with a newly purchased multimeter and he spotted it - in the dark with a trouble light

I had only spent hrs in the daylight comparing the wiring diagram to the wires on the engine and still didn't spot it

Thanks guys for all the suggestions that kept me at it

These forums rock

it happens to the best of us!!!

a pair of extra eyes never hurts anything....especially when you been starring at the same thing over and over.......

 

[starcrafter65]

Re: Engine will not shut off

Success

The frigging main positive battery connector at the starter was touching the post next to it

5 or 6 hrs of grief later my handy buddy was helping me trace wires with a newly purchased multimeter and he spotted it - in the dark with a trouble light

I had only spent hrs in the daylight comparing the wiring diagram to the wires on the engine and still didn't spot it

Thanks guys for all the suggestions that kept me at it

These forums rock

Exact same with me!

"What happened to me was the big fat lead that came off battery and went to the starter (hot) connection on the motor had a big long connector on it at the engine - and actually was touching the stud which the purple common came off of next to it - making the engine "live" all the time. So I had a short from the hot to the purple. I would look for that."

Took a guy with a multimeter to help me find it in 2 seconds!!

 

[DarrinT]

Re: Engine will not shut off

Next possible problem is since the coil was receiving alot more unresisted juice it was running so ridiculously hot that you couldn't touch it barehanded and at one point the first coil wouldn't start the engine and so I swapped in a second that was cold

so I'll have to look up how to test the two coils I have and make sure they are still good- or just buy a new one

any thoughts on marine vs auto coils? (is there a marine coil?)

 

[starcrafter65]

Re: Engine will not shut off

Next possible problem is since the coil was receiving alot more unresisted juice it was running so ridiculously hot that you couldn't touch it barehanded and at one point the first coil wouldn't start the engine and so I swapped in a second that was cold

so I'll have to look up how to test the two coils I have and make sure they are still good- or just buy a new one

any thoughts on marine vs auto coils? (is there a marine coil?)

Look familiar? My big red feed with the long end was touching my purple lead on the coil....what are the odds.

As far as smoking....I have run since then and no problems....I mean the motor that I ran!!

Good luck!