66 250 Monza wire diagram

[Davescycles72]

On the regulator the brown wire is charge warning lamp. Green is ground,red hot, yellow stator,blue is to convert to 12v by cutting wire,and tape ends. I olm checked every wire to destination but no go, only charge indicator.

[Davescycles72]

Success, finally got all in order, special thanks to a friend Bud Laws in Johnson City Tn. Bud is a vintage restorer with experience in foreign cars and bikes. The wiring diagram is a guide for the 66 Monza,but by no means a template. Member Hans in Germany,got some color out of the schematic which was very helpful,through an app.

Using the electrex RR163 regulator with the stock headlight board will work without anymore switching gear, it is a matter of trial and error under power. My basket case project came with many parts that was not correct for the model,and had to be replaced. Special attention needs to be paid to horn,and brake light,and bulb holder, as these 50 year old components do not have good contact surface from years of oxidation,and paired with replacement parts that don’t fit like original. Which though you have corrections correct,you chase your tail because of bad connections.

Example: headlight bulb holder wired correctly doesn’t work,wiggle the bulb and It works. Also confusing is some circuits need common grounds to function correctly. So don’t waste time using the frame ground on your test all the time. Also if you are fortunate enough to have a stock wire harness, clean the contact surfaces meticulously, olm test continuity,not in circuit. I found corrosion issues inside insulated wires, so depending on the testing VOM, use accurate ones.

I had a new 160 jr when I was a kid,and it was great no issues, cousin had a 250 Monza I was envious. I have restored a lot of vintage bikes in my life,with much more complicated components,but never had the issues I have had with the 250 Monza wiring.
The 66 N/C, in particular with the introduction of the large lighting board,and no decent diagram is the problem is it vague,and in areas incorrect, in other words when you get stumped disregard it,and move wires about until it works correctly switched and unstitched.

I now have to clean up the wiring and button everything up,with my freshly painted parts. I hope something I have learned will be of assistance to someone under taking this project. I will post a pic of my finished project here soon. Also I will try to be of assistance to help members if I can. My 305 super hawk will be a breeze after this. LOL
Dave

[ducwiz]

Hi Dave,

congratulations, you made it !
This is the "app" I used to enhance the wire colours in your schematics:
https://www.irfanview.com/main_what_is_engl.htm
It is free for private use, and an excellent tools for working on graphics, photos etc.

Hans