Just a quicky....
I have a second-hand Acewell Ace 3100. I have seen all the wiring diagrams floating about on the tweb but none have seven wires coming from the unit!
Black=ground
brown=battery +
red=switched +
green=speed sensor
white=speed sensor
yellow=tacho input

and I also have a blue wire! I've poked 12v at it to see if it was a main-beam indicator but nowt occurred.
Any suggestions?!

Odd, the Acewell 3100 manual doesn't show a blue wire, but a randomly chosen other dash (3251W) shows the blue wire as a fuel sender input. All the manuals and wiring diagrams are on Acewell's own site.

Just had a look at the 3100 manual and it mentions an "optional" fuel meter, so that is probably it.

[Edited on 1/8/15 by SteveWalker]

Yup. I've also had a look at the other diagrams and found the blue fuel light wire. Mine has no fuel gauge.

Are you absolutely certain it's a 3100, not a 3150? (only some had the no'. on the front of the unit) which had the fuel gauge - if the fuel gauge is turned off in the software it doesn't show up on the screen. If you run thro' the software setup, you would get to the section with fuel gauge settings & should be able to set fuel gauge to off, 100, 250 or 500 ohms

When talking about the actual computer not the warning light surround I don't recall Acewell ever using blue for anything other than fuel

I've scrolled through the settings and get:
12/24hr
time
RPM
SPC
c
MPH/KMH
then back to the 12/24hr. No fuel gauge settings.

Don't know what else to suggest, Acewell Uk are on their summer shut down at the mo, but I will ask them when they get back

There's no panic. I'm just curious as to what the blue wire is for. It may be to control the turbo-mega-boost.......