98 SN: Speed Control via Horn?!?

[mfjaegersr]

I hope it’s just a grounding issue, but I had to use the horn twice in the last week...on second thought, the horn didn’t help at all...to chase the geese away from three ball as we approached. (they had slipped into the course after the previous pass)

 

The horn honks worked like a SPEED UP control for the Perfect Pass and the display essentially goes ? until the end of the pass. I enjoyed it from the tow line end Tuesday am when Buddy Driver honked at our lake owner as we rounded the turn island. ‘This doesn’t feel like thirrrtyyy twooooo....’ More like 38...!

 

Strict No Horn policy in effect until I can rectify the sitch. Has anybody else experienced this Horn-to-Perfect Pass connection before?

[DavidN]

Reminds me of this thread...

https://www.themalibucrew.com/index.php?/forums/topic/70703-horn-honk-causes-boat-to-speed-up/&tab=comments#comment-1077383

 

Apologies for the long link. :*

[Tom351]

I have never experienced it, but maybe grounding, or maybe the horn uses enough power that the voltage to PerfectPass drops just enough for the system to cut off- and it makes sense that this would cause acceleration because of how perfect pass works: by reducing throttle setting from wherever the throttle lever is pushed to by the driver.

[vtjc]

I had a similar issue with my 99 MC SportStar, using the horn would cause the PerfectPass to cut out. I rarely used the horn so I never bothered to investigate it further. PP does seem sensitive to voltage drops.

[BraceMaker]

Best bet for Perfect pass is to run an entirely separate wire pair from the battery to an on/off switch to the gauge, if obsessive you can use a relay connected to the ignition switch to turn on/off power to that separate pair.

 

The effect is that the PP gets as much power as it needs regardless of other items that could be messing w/ your power.

[KRoundy]

What year boat is this on? I'm fighting a similar issue on my 1993 SN. There is a great little thread about this on CCF: Installing a relay for PP

[mfjaegersr]

@KRoundy ‘98

 

Great thread; thanks for the link!

[KRoundy]

Oh, the year is in the title of the thread... :p

[BraceMaker]

@KRoundy - The year doesn't so much matter with PP - the system has really not changed on the engine side in basically forever.

 

The trouble with PP is that the servo drive is a beast, notice it has a big honking hot resistor - which I believe is between the two phases on the motor as a common which makes me think it basically acts like a brake for the servo so it doesn't slip unless it is signaled (but i'm not an electrical engineer)

 

So you have a long small gauge wire that brings power to the ignition switch from your starter's battery terminal, and a long small gauge wire that brings ground from the block to the dash. Those 2 wires then power everything that gets juice out of the dash, gauges, lights, the horn, the blower, the bilge, the tach and of course Perfect Pass, which has a control module, the gauge, and the big honking servo that it needs to power.

 

When you watch the "voltage" in the perfect pass display you will often see it read quite low compared to battery voltage, this is just due to the amount of load it puts on the system. When directly wired and particularly directly wired with excessively heavy duplex marine wire (like 8 gauge) it will read very close to battery voltage and usually perform better.

[mfjaegersr]

@BraceMaker Thanks for the insights. Add ‘the heater’, which was running at least for one instance.

 

@KRoundy ? (didn’t see the value in calling you out. For that (yr question). I’m thinking about the relay project; have you looked into ordering the parts (relay, mostly)?

[KRoundy]

I have my relay and in-line fuses sitting in my garage and plan to do the installation this weekend. I have to replace my steering cable so I'm going to be tearing apart that area under the bow and plan to kill two birds with one weekend of effort.

 

@BraceMaker Good point. I know there are issues with grounding in some early-90's Nautiques (like mine), but your point is spot-on. The PP is a high-draw system and those tiny and long wires are already loaded up pretty well.

[jhughes]

The horn takes a big spike of voltage to run and PP is sensitive to voltage so there's obvious correlation there. That original relay thread on CCFan is mine, still going great 8 years later.

[BraceMaker]

@jhughes do you like yours with the relay?

 

I have mine on a mechanical switch which I generally like because I can flick it on and get everything set up before starting the boat and I can press the off button and physically switch off the power to the PP for cruising at night.

 

But I have been considering putting a relay and just running the PP on/off switch between the ignition and the relay.

[markn]

We had the same issue on our 1995 Nautique. Ended up powering the PP directly off the battery rather than a breaker. No more voltage drops due to the horn.

[hogexpress]

Same issue on '00 SN. Fixed same as markn.