V Boost On/Off Switch Issue

[grislyadam]

Had my 99 Max for a few years now. It came with an On/Off Boost switch on the switchgear but this has now seized. I have taken it off to look at the wires to see if there was just two then I could connect or disconnect so that the V Boost runs as normal. There are, however, four wires (as pictured). The V Boost whirrs as per when switching on but seems to be off at 6000 revs plus. Any ideas what wires to connect ? Cheers.

 

[02GF74]

You say there are 4 wires yet I only see three soldered to the switch.

Also I can see the ends of the wires so they are connected to nothing.

Usually a DPDT switch is used to supply power to open the servo motor valve and switched to reverse power to close the valve, that does not look like the one you have.

Remove the left hand scoop and the vboost module is the thin rectangular black plastic box furthest from the front.

Take a photo and we'll take it from there rather than risk damage to the electrics by guessing.

 

[Fire-medic]

Look here.
European:
https://www.vmaxforum.net/attachments/yamaha-v-max-custom-wiring-diagrams-2-compressed-pdf.28835/

USA:
https://www.vmaxforum.net/attachments/yamaha-v-max-custom-wiring-diagrams-4-compressed-pdf.28837/

 

[grislyadam]

Many thanks for the wiring diagram link (best I've ever seen !) and for the above advice.

I cut the wire thinking it would just be 2 wires but there were 4. I cannot see where the wires go so will get an opportunity tomorrow to get the airbox off together with the scoops and see where the wiring leads me. I know from my other previous V Maxes that the wiring behind the left hand scoop is not standard but will get a better idea when apart. Will upload the photos when my boss stops e-mailing me and giving me more work !

Cheers

Adam

 

[Fire-medic]

"...when my boss stops e-mailing me and giving me more work !"

Good on-ya for having work during this time. Work first, play later.

I did a color print job of the .pdf, it helps when trying to trace something, along with the legend for the colors.

 

[grislyadam]

Well I feel a bit of a dick here without having done my homework first. From under the rev counter console I pulled out a small black box that the four wires went into. Out of that were wires that went into 2 uncoupled connector blocks that were just sat there gathering dust. The only thing connected to anything was an earth wire to the frame. It was obviously disconnected some time ago. I enclose a snap of the wiring under the left hand scoop, which show that there has been some rewiring but all looks in place ? When I get my replacement throttle delivered tomorrow, I'll put it all back together and head up the motorway for a blast. May be that I was not gunning it enough to kick the V Boost in. Less panic and more patience methinks. Thanks for the advice chaps. Adam

 

[one2dmax]

Not sure what that is doing?

 

[desert_max]

Couple of relays. Could have been aux lights, a horn... who knows?

 

[02GF74]

Damn, I should know the numbers but from memory the vboost start to opens the valve at 4300 rpm, fully open at 6500.

So in theory you could test this in the garage, remove tank and air box and observe the cable pulled, could be quite noisy though!!!!!

BTW I think I can see the connector for the indicator unit so those two modules appear to be additions. It's really annoying when people make additions or modifications to electrical systems, they don't include a circuit diagram, it would not gave been difficult or time consuming to draw up on a post it and cello tape it to the bike.

 

[Zeus36]

V-Boost starts to open at 5,750 RPM and should be fully open at 8,000.