http://cgi.ebay.co.uk/YAMAHA-DT175MX-DT175-DT-MX-FRONT-BRAKE-LIGHT-SWITCH-/220783641319?pt=UK_Motorcycle_Parts&hash=item3367bb02e7
Remember I asked you if you had a new loom? you said no its a 4J3 loom, well the bad news is thats the wrong loom, its a DT125MX loom from a later version to yours I think. No wonder things dont match up.
so how did you come to have that and what happened to the original?
http://cgi.ebay.de/Yamaha-DT-125-MX-Haupt-Kabelbaum-Wiring-4J3-82590-40-/140517010991?pt=Motorrad_Kraftradteile&hash=item20b7776e2f