Alpha one shift interrupt switch

[gavincollison]

Have a mercruiser 190 with alpha one is it absolutely necessary to have the shift interrupt switch fitted as I don't have one

 

[ENSIGN]

Re: Alpha one shift interrupt switch

You better get one.Without the switch working you won't be able to take the boat out of gear unless you shut the engine off.

 

[Bondo]

Re: Alpha one shift interrupt switch

Have a mercruiser 190 with alpha one is it absolutely necessary to have the shift interrupt switch fitted as I don't have one

Ayuh,... Without it, you won't be able to come outa gear, 'n it'll stretch the cable, Badly...

 

[dubs283]

Re: Alpha one shift interrupt switch

Have a mercruiser 190 with alpha one is it absolutely necessary to have the shift interrupt switch fitted as I don't have one

you will hate docking your boat without one

cable stretch and skipping through nuetral are common occurences when the switch fails/is bypassed

the switch is there for a reason, if yours is broken you will have to repair the switch, they are nla from merc

 

[Don S]

Re: Alpha one shift interrupt switch

While that switch is NLA from Mercruiser, they do make a replacement kit that uses the newer style shift interrupt kit.
The kit part number is 864363A1

 

[gavincollison]

Re: Alpha one shift interrupt switch

Thank you all for your replies. I have the Base plate and all of the mechanical parts. This seems to be working fine. The only thing that is not fitted is the microswitch itself. Does anyone have a good part number for one of these and does anyone know where the cables should go?

 

[gavincollison]

Re: Alpha one shift interrupt switch

As an alternative to tgetting a part number can some one tell me if this is just a basic microswitch. Pressuming that when switch is in the relaxed position it is open circuit, then perhaps when you go to change direction it grounds out something (coil maybe) so it would go closed circuit?
The reason I ask is that I used to work in an aircraft maintenance hangar (still have lots of friends there ) and i remember that on most aircraft doors they use a microswitch to sense when it locks. It looks spitting image of this image
Mounting points maybe different but that can be modified. I shall see if i can aquire one.
Just need to know circuit diagram/information please?

 

[achris]

Re: Alpha one shift interrupt switch

Many people have tried to replace the switch with a 'generic', all have failed. You need the kit Don told you...

 

[Sandbank]

Re: Alpha one shift interrupt switch

From experience...the boat can be very dangerous without it as sometimes it may just not come out of gear. Not to mention the strain you are placing on the lower unit gears.

 

[gavincollison]

Re: Alpha one shift interrupt switch

Ok To reassure you all I promise not to put the boat on water untill the microswitch is up and running. Everything I need is there so i'm not willing to pay ?100+ for a microswitch.
Guy's it's a microswitch, is there more to it than a simple switch mechanism? Does it have an internal resistor or diode? Has anyone metered one of these bad boy's to check for resistance?
I've read a couple of posts and people have wired them back to front and they wont work? So i'm guessing maybe a diode.
Has anyone taken one apart to look at the internal workings/components? Internal pictures?

This post could save alot of people with similar problems a bit of cash.

 

[gavincollison]

Re: Alpha one shift interrupt switch

Fyi the switch grounds the negative connection of the distribution cap which prevents a spark.

 

[MarkSee]

Re: Alpha one shift interrupt switch

Fyi the switch grounds the negative connection of the distribution cap which prevents a spark.

DonS write up includes pictures; in case you have not seen this.
http://forums.iboats.com/showthread.php?p=1930449#post1930449

Mark

 

[Fishermark]

Re: Alpha one shift interrupt switch

Guy's it's a microswitch, is there more to it than a simple switch mechanism?

You are correct - it is a simple switch. My concern would be longevity. Most switches do not last long in a salt water environment (or even fresh water) unless they were specifically designed to do so. Just sayin.....

 

[Scott Danforth]

Re: Alpha one shift interrupt switch

find one that is IP65 rated at the minimum.

 

[Technorunner]

Re: Alpha one shift interrupt switch

i have found one thats IP67 rated
https://www.elfa.se/elfa3~se_sv/elfa/init.do?item=35-831-84&hst=1
its in swedish but you see the pic of it and it costs 2.50 dollars guaranteed to work for 10mil operations that should work right ??

 

[Don S]

Re: Alpha one shift interrupt switch

guaranteed to work for 10mil operations that should work right ??

You tell us when you get it installed.

 

[Technorunner]

Re: Alpha one shift interrupt switch

i did already order one to try 10 min ago. With that price IF it works sure will be nice. And you can chose with the connections if you wan NO or NC. Do you happend to know how long the arm with the roller on it should be?

 

[ktbarrentine]

Re: Alpha one shift interrupt switch

IMHO...The blue ink in Don's signature says it all.... After all...It is a B.O.A.T.!! I recommend go big, do it right, or risk a tow back to the ramp.....

 

[Technorunner]

Re: Alpha one shift interrupt switch

I was bored at home so i opend the microswitch. And mercruiser was not doing it big with those switches lol. Its not sealed at all. Irepaired mine in 10 minutes after opening it i also changed min to NC since i need it for my injectionsystem. I took a pic after i made it NC but just for you to se how simple it is one of the connectors was burnt.First i drilled of the brass tubes holding it toghether. I opend it up. It took me approx 10 min with getting my drill. So i took a fine sandpaper end removed all that was burnt. Voila it works again. just puted in some batterypole greas and sealed it up with some silicone. So i canceld the order of the Microswitch since this was so easy. I will do it on my other as well.

 

[fishrdan]

Re: Alpha one shift interrupt switch

I used an "off the shelf" micro switch for my MC-1's shift interrupt switch. I'm not sure how close it is to an Alpha 1, but here's a couple pics of the setup, it needs an adapter bracket. (I don't remember the switch P/N, but have posted it before, look in the archives) Been using it for the past 2-3 years without issues.