'86 Westy

Hi, I have this kit installed and it has worked fine.  Yesterday I took
off the ground to clean it down to the metal and today it no longer works.
 I have one question about the black and red striped wire coming from the
starter battery (along with the blue and thick red one).  Where is this
wire supposed to connect to?  It is not connected to anything and I cannot
remember if it is supposed to.

Thanks
Gregor