Shift interrupt question

[SteveH_1919]

I think the shift interrupt switch (SIS) on my 97 Maxum has bone bad.

When in the water, every time I shift from FWD to N, I blow a 15A fuse and the engine shuts off.

When I re-powered this boat, the GRN/WT from the shift interrupt switch and PUR (12V, which can be traced to the 15A fuse) have a common location which is on one side of the new oil pressure switch.

Here is my thought process.
I read the sticky on the SIS
The shift cable was replaced 2 years ago with no issues after replacing. The boat sat for about a year before re-powering.
When I return to neutral and the boat is in the water, the SIS is overloading the circuit, shutting off the electric fuel pump and blowing the fuse.

I will start the troubleshooting process with the credit card and replace the SIS.

Does this sound logical? Any other ideas?

Thanks,
Steve

 

[Alpheus]

Re: Shift interrupt question

No.

the GRN/WT from the shift interrupt switch and PUR

GRN/WHT should be going through the switch to black wire (ground) Your causing a short...

 

[Bondo]

Re: Shift interrupt question

Does this sound logical? Any other ideas?

Nope,.... Sounds like the Cable again... Did it get Wet during that year,..??

Your wiring sounds wrong as well,... It should stutter the igntion, not blow fuses...

 

[SteveH_1919]

Re: Shift interrupt question

Thanks for the replies.

Yes the boat got wet after the shift cable replacement. And I had no problems from the shift cable replacement.

The motor went bad and I repowered.

I agree the wiring sounds weird. I am enclosing a pic of the wiring for the new engine.
The wire from the shift interrupt switch to the oil pressure switch is the WHT/GRN wire on the interrupt switch.

Both of the replies point to a wiring issue. When you start blowing fuses, it is a good indication that there is a wiring issue.

I guess I should call the people I go the engine from and get a clarification, too.

Thanks again.

 

[Alpheus]

Re: Shift interrupt question

Like I said you have it wired wrong...

 

[SteveH_1919]

Re: Shift interrupt question

Sorry Alpheus...
Maybe I am just being dense, here.

On the diagram that came with the new engine, one wire from the shift interrupt goes to ground (supposedly black).
The other wire WHT/GRN is connected to the purple in the harness, which then connects to the oil pressure switch.

What do I have wrong?
BTW, you appear to be just around the corner. I am in Chesapeake, VA

Thanks,
Steve

 

[Alpheus]

Re: Shift interrupt question

The other wire WHT/GRN is connected to the purple in the harness, which then connects to the oil pressure switch.

That wht/grn wire should be hooked up to another wht/grn wire coming out of your distributer...




That purple wire should not be there. Think about it. Everytime tou hit the shift interrupt switch you are causing that purple wire (+) to short to ground and blowing your fuse.

 

[SteveH_1919]

Re: Shift interrupt question

Talked to the guys I bought the engine from.

I indeed have a wiring issue.

Gotta go and see if I trashed the plug i need for the distributor. OOPS.
Trash day tomorrow. Yikes.

More to follow.

 

[SteveH_1919]

Re: Shift interrupt question

An inspection of the shop trash cans yielded nothing in the way of the needed plug.
RATS!
So... now I gotta go figure out where to get a replacement plug and find out the wiring of the plug.

Steve

 

[SteveH_1919]

Re: Shift interrupt question

SWEET!
I looked in another box and found the plug in question.

Whew!!!!!

OK. Now, I gotta think about Battening down. They have posted Hurricane warnings for the NC coast.

More after dark.

 

[SteveH_1919]

Re: Shift interrupt question

Based on a review of the schematics, for every engine I see in the manual, there is not 12V going to the shift interrupt switch.The DWG that came with the new engine is shows 3 wires. The guy at the engine place said some of the shift interrupt switches had 12V to interrupt the RPMs and allow the gears to disengage and some used a ground. See attached.

My switch only has 2 wires. I will presume the BLK wire goes to GND (which it does) and the wht/grn goes to the distributor.

I will also presume my engine uses a ground to interrupt the RPMs. Cuz the 12V blows fuses.

I will hook up the wires for the ground and see what happens when I am in the h2o...after Earl goes by.

Thanks for the advice.
Steve

 

[Alpheus]

Re: Shift interrupt question

Its gonna work. There is never no power going through the interrupt switch. Like I said you are causing a direct short every time the switch is closed...

 

[SteveH_1919]

Re: Shift interrupt question

It sure worked.
Thanks for the advice.

Boat ran great.