Shift interrupter switch...where is it?

jillann

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Jun 12, 2010
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2
I have a 86 SeaRay Seville and she will crank but not start. I belive it might be the Shift interrupter switch. Is this something that can be repaired while the boat is in water or do I have to pull it and take to a mechanic? Also, where exactly is the Shift interrupter switch? Any insight will be appreciated. TIA
 

wire2

Lieutenant Commander
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Jun 25, 2007
Messages
1,584
Re: Shift interrupter switch...where is it?

The exact location depends on the make of the outdrive, and which engine you have, but typically it's mounted on an aluminum plate ~ 3" x 8" at the end of the shift cable from the helm. It's probably bolted to an exhaust riser. Look for a small switch on it with 2 wires from the harness.
 

swihartart

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May 4, 2009
Messages
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Re: Shift interrupter switch...where is it?

Here's what it looks like.
shift_interrupt.jpg


After engine stalls, don't move shifter at all, If the roller is NOT centered, the switch contacts have closed and therefore killed the engine.
 

HHIBouy

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Jan 6, 2010
Messages
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Re: Shift interrupter switch...where is it?

On my 87 Ebbtide M/C, if the shifter is not in netural it will not even turn over let alone start. You may have some other problem.
 

Jimmy1960

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Jun 5, 2010
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Re: Shift interrupter switch...where is it?

I just had mine replaced. Due to time constraints I let the mechanic do it. It was relatively affordable. Just over $100.00 for a new switch plate assembly with new style button switch and one hour of labor. If I would have tried it probably would have been a few hour ordeal.

Are you able to test the switch to determine if it is stuck in closed postion.
 

nola mike

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Apr 22, 2009
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Re: Shift interrupter switch...where is it?

On my 87 Ebbtide M/C, if the shifter is not in netural it will not even turn over let alone start. You may have some other problem.

different switch. if the SIS is stuck, the engine will turn over with no spark.
 

jillann

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Re: Shift interrupter switch...where is it?

How to I test the switch?? Its a 1986 merch 170 4 cyl, if that helps
 
Joined
Jun 15, 2009
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Re: Shift interrupter switch...where is it?

I have a 86 SeaRay Seville and she will crank but not start. I belive it might be the Shift interrupter switch. Is this something that can be repaired while the boat is in water or do I have to pull it and take to a mechanic? Also, where exactly is the Shift interrupter switch? Any insight will be appreciated. TIA

I have a Merc 3.7/LX and the swith is on the side of the block. There are rods which push a small cam on the side which engages the switch. That you can fix on the water. Others I have heard are in the throttle compartment.

-- bk
 

Bondo

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Apr 17, 2002
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67,703
Re: Shift interrupter switch...where is it?

and she will crank but not start. I belive it might be the Shift interrupter switch.

Ayuh,.... What lead you to Believe That,..??

What Testing have you done to this point,..??
 

md-lucky

Petty Officer 2nd Class
Joined
Aug 20, 2008
Messages
168
Re: Shift interrupter switch...where is it?

Mine is up near the top of the engine, on the starboard side:

It kept doing this:
shift.jpg


I imagine if you had a new part, it would be very easy to fix. I pulled mine off and cleaned it very well, then lubed it up with a high quality silicon spray. No issues since.

You CANNOT adjust this out of the water. I spent a lot of time getting it just right on land, only to have it not be even close once we hit the lake. Replace it and do your adjustments on the water!
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,334
Re: Shift interrupter switch...where is it?

Md lucky, you have an OMC, he has a Mercruiser.
 

Don S

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Joined
Aug 31, 2004
Messages
62,334
Re: Shift interrupter switch...where is it?

I seriously doubt the shift interrupt switch is causing your no start problem. More likely bad points or no gas.
Your shift interrupt switch is located on a plate with the shift cables going to it, on your engine, it should be on the side of the exhaust manifold.
Below is a drawing of the plate and shows the switch.
To test, remove either one of the wires going to the switch and see if it will start.

attachment.php


PS: if you go here http://forums.iboats.com/showthread.php?t=251571 you can download the OEM service manual for your engine. You want #8 for the engine, 6 for the drive.
 

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tschmidty

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Mar 24, 2010
Messages
462
Re: Shift interrupter switch...where is it?

It may or not be the switch, but you can test that easily enough by disconnecting the wires to it. It works by grounding the coil and operates in an open position normally so disconnecting any of the wires on it and making sure they don't ground should do it. You can also disconnect the grey wire on the coil as well.

If it's the shift interrupt it wil absolutely not fire at all. If you hear it trying to start it is not the shift interrupt.
 

wil7483

Petty Officer 1st Class
Joined
Jan 19, 2007
Messages
377
Re: Shift interrupter switch...where is it?

I have a 86 SeaRay Seville and she will crank but not start. I belive it might be the Shift interrupter switch. Is this something that can be repaired while the boat is in water or do I have to pull it and take to a mechanic? Also, where exactly is the Shift interrupter switch? Any insight will be appreciated. TIA

If it is trying to start then it is not the shift interrupt switch. Time to look elsewhere.
 

nola mike

Captain
Joined
Apr 22, 2009
Messages
3,011
Re: Shift interrupter switch...where is it?

If it is trying to start then it is not the shift interrupt switch. Time to look elsewhere.
the SIS grounds the ignition. it WILL crank, but you won't get spark.
 

LuciusII

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Mar 14, 2008
Messages
1
Re: Shift interrupter switch...where is it?

I am having a problem where the shift interrupter rocker arm does not consistently drop back into position when going into gear. This leaves the ESA switch on causing the engine to stumble and preventing me from going anywhere. In these cases I jiggle the throttle and the rocker arm usually comes back and turns off the ESA switch. Sometimes, when at idle in gear and with the ESA switch off, I give it gas and the shift interrupter rocker arm moves and turns the ESA switch on. Not sure why the shift cable moves after in gear and that is something I need to further research.

In an attempt to resolve my issue I played with the shift interrupter rocker arm spring tension (part #4 in Don's diagram) by pulling off the rocker arm, pulling out the spring, and bending it by hand. I initially set the spring tension too high and the ESA switch never went on. I now have the spring tension set to where the rocker arm now springs back more consistently when going into gear and also does not move as frequently when giving gas. I've only tested out of water and hoping I don't get different behavior when the prop has real load.

I expect to continue having intermittent problems where the rocker arm doesn't always reset when going into gear and moves when in gear and giving gas. I will be doing more research on how to resolve this and suspect it may involve shift cable adjustments or possible replacement. If anyone has insight on this please let me know.

I've attached a photo showing the things I've talked about for reference.

Thanks,
Luke
 

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