2015 Scarab 165 Electrical

[rocky5]

2015 Scarab 165 Electrical Issues:
Added house battery and 4-position switch and apparently damaged something.
Now:
1. Instrument cluster does not activate.
2. Ignition switch:
a. Accessory mode (left key turn) not working
b. Off - OK
c. Engine on now starts the motor (right key turn)
d. Engine start same as engine on position (full right key turn)
All fuses are good.
Changed both relays. Returned to original battery configuration. Still same symptoms.
Any ideas?

 

[Luc Lafreniere]

When you say "all fuses are good", did you chec the fuse box in FRONT of the driver? Because many 165 owners don't know there are two fuse boxes. One by the battery (the one with relays) and a second one hidden in front of the driver. Assuming your profile is correct, the 2015 models have it easily accessible under the hood in that location.

 

[rocky5]

I did check the back labeled fuses and the box in front which are not labeled. There is a tall 6A fuse that I did not check because it is opaque white and cannot be checked visually.

 

[Luc Lafreniere]

Here's the diagram for those for future reference. The tall one is probably the diode for the lights.

The fact you have no cluster really implies it's that fuse as labelled in that diagram.

 

[rocky5]

So NAV Light Diode is for the LCD cluster?
What about the engine starting without turning to the starting position?

 

[Luc Lafreniere]

Not quite. Diode is just a diode and not a fuse. It's for the navigation lights only. Nothing to do with the cluster. Sorry, my sentence was written very quickly. The other fuse that says Display... I'd recheck that one for the cluster.

As for the engine starting... uncertain there. lol I'm not sure what was done... but sounds like you friend something somewhere. Hard to diagnose remotely except using a multimeter and checking each connection manually. Things could have fused... and the ignition is messed up or other.

One nice thing about the older 165 models is that you can easily access all the wiring behind the cluster. 6 screws to remove the black plastic tray and presto, all wiring is there. The newer models are much more of a pain to access.

 

[rocky5]

A poster named ScarabMike had written in 2017:
If you place your key on "run" position, and you bypass the solenoid, the engine will crank and start IF the solenoid was the issue, guess what, it did not run.
This suggests mine is bypassing the solenoid (involuntarily). Any idea what fail would lead to that?

 

[Luc Lafreniere]

Sorry, can't help you there. He was definitely a very knowledgeable guy. Just not much in the boating world anymore. I suggest you cross-post this thread under the Scarab section too. You may get more traction there sinc many Scarab folks only track that sub-section. The General section is dominated by Yamaha related content. No issues with that personally, but because of it, many don't follow the general thread if they own a Scarab.

 

[rocky5]

Thanks. I'll try him directly for possible feedback.

 

[rocky5]

Does display come on with key to left accessory position or only when engine on?
I’m going to replace starter solenoid this week. Seems like most likely culprit as key to engine-on runs starter which it should not. Key to starter full-right should be required and I assume solenoid is the controller.

 

[Luc Lafreniere]

Pretty certain key in accessory position only gives power to things like a stereo. Not your cluster. Cluster turns on when your key is turned one notch to the right and should of course remain on when starting the engine.

 

[rocky5]

Appears that “on” and “starting” are merged. Hoping starter solenoid solves that and also relays display status.

 

[rocky5]

Summary: Starter runs when key is "ON". No cluster display.
Updates:
1. Replaced starter solenoid. No change.
2. Replaced key switch. No change.
I read in a Seadoo forum that this (always running starter) could be due to a short in the MPEM (relay/fusebox).
When weather clears, I'll inspect the fuse panel for burns and then start removing fuses and testing starter path with a multimeter.

 

[rocky5]

Any chance you could let me know the wire colors to A I B S ignition switch connections?

 

[Luc Lafreniere]

Sorry, my boat is in offsite storage for winter and I don't have any pics that shows that.