OK....another shift interrupter question please

[magic11305]

I'm still working on getting my 5.7 mercruiser hooked back up in the boat after a rebuild. I was reading some threads here about shift interrupter problems and realized I didn't remember one on my engine. I also have a 20' Reagal with a 3.0 Mercruiser, so I know how it is hooked up. I checked and my 5.7 does not have the electrical part for the interrupter. It has the spring plate but no signs of anything else ever being installed there. I am assuming that all sterndrives use the shift interrupter for ease of shifting out of gear?? Any thoughts? If I need to put one on, where would I start looking for one?

 

[alldodge]

Re: OK....another shift interrupter question please

If you have a Bravo drive there is no interrupter switch. Which drive do you have and what is the engine serial number.

 

[magic11305]

Re: OK....another shift interrupter question please

Don't have the serial number, was originally Michigan Motorz crate engine, 5.7 vortec, 2008. Running an Alpha one drive.

 

[alldodge]

Re: OK....another shift interrupter question please

Don't have the serial number, was originally Michigan Motorz crate engine, 5.7 vortec, 2008. Running an Alpha one drive.

Is the boat a 2008 or just the new engine?

 

[Bt Doctur]

Re: OK....another shift interrupter question please

did the old motor have it, if it did where did it disappear?
are you positive you have an Alpha and not Bravo?
cant shift an alpha without the interupter.

 

[magic11305]

Re: OK....another shift interrupter question please

Yea, positive it's an alpha, 2011 SEI 1.47. I have all the paperwork for the life of the boat. The engine is a 2008, boat is 1980 Sea Ray 260, that im doin a restore on. There is no sign that one was ever on there, after reading other threads, I went out and looked. I also didn't have parts left over when I finished putting everything back together. I thought that the interrupter was needed on alpha drives. Don't know how the po was able to operate it.....

 

[magic11305]

Re: OK....another shift interrupter question please

Thank you for the input

 

[alldodge]

Re: OK....another shift interrupter question please

Looks like you need to install the original type
http://www.mercruiserparts.com/Show...70&bdesc=SHIFT+BRACKET+AND+REVERSE+LOCK+VALVE

or upgrade to new design

 

[magic11305]

Re: OK....another shift interrupter question please

The plate and spring are there, the electronics are what is missing. Guess I'll have to give it another closer look tomorrow to be sure. I have the delco voyager ignition, where does the lead from the interrupter go? I think one is to engine ground.

 

[magic11305]

Re: OK....another shift interrupter question please

Also there are no rollers like on my 3.0?

 

[thumpar]

Re: OK....another shift interrupter question please

Have you driven this way? The won't shift out of gear if it not there on an Alpha.

 

[magic11305]

Re: OK....another shift interrupter question please

No, I got the boat as a project, I'm retired...wife says it keeps me off the streets and outa trouble, besides I don't golf. The boat was not running when I got it. The po had the new outdrive put on, bottom painted, then it sank to half way up the engine bay. He had just fiished retoring the entire boat, even had you tube videos of it. When they painted the hull, they nicked a hole in the shift boot and didn't tell anyone. He pulled it out of the water and it sat in his yard for 2 years.....engine still full of water, while he took the marina to court.. When I drained the crank case to start my rebuild, I drained 6 gallons of water out before I ever got any milk shake. I was amazed how little damage was done to the inside of the engine! It was a freshwater canal it sank in. I had the cylinders bored .30 over, heads worked, and I have replaced almost everything electrical. Its been a labor of love I guess. Thats my story, thought I'd share

 

[Rick Stephens]

Re: OK....another shift interrupter question please

Awesome story. Wife's right - you could be up to all sorts of no good.

 

[achris]

Re: OK....another shift interrupter question please

If you have a Delco distributor that may account for the lack of shift interrupt switch. Although you still need the switch in either system, the way each system deals with it is completely different. If the person who installed the Delco didn't understand why the switch is there and how it works, they may have ditched it...

To understand here's how each system uses the switch...

Thunderbolt IV and V. The switch is normally open, and connected between ground and the output of the distributor sensor. As the load increases on the cable the switch is closed, grounding the sensor output, and the ignition amplifier just stops firing the coil. When the load comes off the shift cable the switch opens and the sensor output returns to its 0 to 5 volt levels. The ignition amplifier continues then to fire the coil....

Delco Voyager. The switch is connected between +12 volts and a terminal on the distributor. When the switch closed, the +12 volts applied causes the internal module to stop firing the coil.

Both systems will work without the switch in place, but pulling out of gear (either forward or reverse) will be tough! Many cables have been stretched or damaged that way... I re-worked a standard wiring diagram a while back to show how a Delco needs to be wired...

Post a photograph of the shift plate and we might be able to identify it and supply you with a part number for a new switch.

Chris......

 

[magic11305]

Re: OK....another shift interrupter question please



Thanks Chris. I have looked everywhere and I don't remember taking the switch off. What type of switch will work with this plate and coil?

 

[alldodge]

Re: OK....another shift interrupter question please

View attachment 215754View attachment 215755

Thanks Chris. I have looked everywhere and I don't remember taking the switch off. What type of switch will work with this plate and coil?

Looks like part number 39670A28 but is no longer available from my previous post No8 above link. Here is the Merc service bulletin on the change out http://www.mercruiserparts.com/bulletins/001/04//2002/EN_01.PDF

Appears you would need plate No 864363A 1

Mercruiser Shift Interrupter Switch Kit 864363A 1 | eBay

Edit: Found the old switch here and there could be others
http://store.oldmercs.com/product_p/39670a28.htm

 

[magic11305]

Re: OK....another shift interrupter question please

Thank You Dodge, I found just the switch on Ebay for 31.00. Better than 171.00 . Does the connector plug in to where the timing shunt goes? It's the only open plug that I can see and from the picture it looks the same.

 

[achris]

Re: OK....another shift interrupter question please

View attachment 215754View attachment 215755

Thanks Chris. I have looked everywhere and I don't remember taking the switch off. What type of switch will work with this plate and coil?

BTW, that shift plate is on the wrong elbow. Should be on the starboard side.... (and up the other way)...

 

[magic11305]

Re: OK....another shift interrupter question please

You are saying it's upsidedown? It looks like if I move the plate to the port side, the front shift cable would be too long? This is where it was mounted when I got the boat, but as I am finding out as I go along, the po was not big on things being correct. It appears that if it ran it was good enough for him. I am one to need things the right way. Thanks for the info, I'll have to take a look at it again tomorrow. Edit....move to starboard side

 

[magic11305]

Re: OK....another shift interrupter question please

After further investigation, the shift plate I have is designed for the roller type switch. I have an extra roller switch from my other boat but I really dont know where to hook the wires. This old roller switch was hooked to the old coil type ignition, this engines ignition is different, delco voyager? Different type of coil. I know I'm draggin this on and on but I'm trying to do things right the first time so thank you all for your patience .