MP5 Wiring Diagram?

[Guyblat]

I'm looking to add a horn to my bike. Is there a MP5 details schematic or wiring diagram that will tell me the voltage and purpose of each connector?

Guy

[Bikemad]

Hi Guy, the horn and lights are both fed with battery voltage direct from their respective switches.

Here are the connection diagrams for the MPIII and MP4/5 but some harnesses now use orange instead of blue for the horn ground connection shown in these two diagrams:





Check out this topic to see more information regarding the horn and light connections.

Alan
 

[Guyblat]

Thanks Alan

[Guyblat]

Alan,

I've got a 12v car horn I'd like to use, can this work with the MP5 kit's 5v setup?
Guy

[Bikemad]

Unfortunately the controller's +5V supply has a very low current output which I would expect to be 50~100mA max (0.05~0.1A) so it cannot be used to operate a 12V horn.

A conventional 12V electromagnetic type car horn will draw a fair amount of current (typically 5~10 Amps) which would still be too much for the majority of cheap DC-DC converters, but something like this 120 Watt 48V to 12V DC-DC converter should produce enough current for a single 12V horn, but you would need to check the current draw if using a dual horn (twin tone) set-up.

In addition to this, you would also require suitable higher current wiring as the existing wiring to and from the horn switch is much too thin.

However, it should be possible to use a 48V relay to enable the existing horn switch to operate the horn by momentarily switching battery voltage to the DC-DC converter which would have its 12V output wired directly to the horn.

Alan
 

[Guyblat]

Great advice, thank you so much.
Guy